Emerging Disease and Zoonoses #17--How now, mad cow

People make terrible jokes about "mad cow" disease. ("Why is PMS called PMS? Because mad cow was already taken.") Pundits use it as an example of an over-hyped disease (and to be fair, estimates of total cases due to the consumption of contaminated beef in the UK have varied widely, ranging from a few thousand up to well over 100,000). Vegetarians note it as one benefit that comes from their soyburgers. Everyone, it seems, has an opinion.

So-called "mad cow" disease, in humans, is a progressive neurological disorder more correctly called variant Creuzfield-Jacob disease (vCJD). This is due to infection with an agent called a prion. Additional background can be found here, but briefly, the prion is actually a misfolded form of a normal host protein (called PrPc, standing for "prion protein, cellular form"). Its a concern to human health largely because the disease swept through cattle herds in the UK in the 1980s, and it is uncertain just how many humans unknowingly consumed contaminated beef--and therefore, how many may eventually develop vCJD.

vCJD is one of a family of transmissible spongiform encephalopathies (TSEs); others in this family include scrapie (which affects sheep), chronic wasting disease (which affects deer, elk, and moose, among others), and another human TSE called kuru (discussed further below).

Kuru was first recognized a half-century ago among the Fore group in the highlands of Papua New Guinea. Investigations showed that the disease was spread by cannibalism (though, at the time, the causative prion had not yet been identified). Women and children became infected during ritual consumption of the bodies of deceased relatives. Men did not participate in this, and were largely spared from development of kuru. This practice was outlawed in 1954, and ceased by 1960. Around this time, extensive surveillance for kuru in this area was instituted, initially identifying a relatively large number of cases (approximately 200 deaths per year in the late 1950s). And while incident disease cases dropped dramatically over the decades (the average incubation period was found to be ~12 years, similar to one form of vCJD), surveillance has continued.

A new Lancet paper reports on recent results of this surveillance, detailing cases of kuru diagnosed over the last decade--at least 36 years removed from the end of cannibalism in this group, and likely over 50 years from the time of exposure. From 1996 to 2004, 11 cases were identified.

The kuru cases they found during this period were unique for several reasons. First and most striking, because most of them were in men. As I mentioned earlier, men make up a small percentage of kuru cases--of the 2700 total cases diagnosed during the course of the epidemic, only ~2% were in men (versus 64% in this study). This is likely because their only exposure comes during childhood, when they participated in the ritual feasting, while women were exposed throughout their lives. After about the age of 6, boys were taken from their mothers and brought up in the mens' house, where, the paper notes, "they participated little in feasts and did not eat the brain, by far the most infectious organ in kuru." The male cases in this study ranged in age from 46 to 63 years old, suggesting an incubation period of over 50 years if most of their exposure occurred before the age of 6.

DNA was available for 10 of these cases. A genetic analysis of the several loci was undertaken, as genetic susceptibility to prion disease has been documented both in humans (in the case of vCJD) and in animals (to various TSEs). In humans, for example, a polymorphism in PrPc appears to increase susceptibility to both the acquired CJD as well as what's known as "sporadic" CJD (in which the prion is not acquired exogenously). People who carry two copies of this particular allele (with a methionine at codon 129 of the PrPc gene rather than a valine) represent about 38% of the European population, but thus far, have accounted for almost all clinical CJD cases. When this gene was examined in those 10 fatal kuru cases, 8 were found to be heterozygotes, with one each homozygous for valine and methionine at codon 129.

What this suggests is that, perhaps, those with a particular genetic makeup (such as those homozygous for the methionine129 allele) may be the most susceptible to TSEs, making them the first wave of TSE cases in an epidemic. Therefore, what we are seeing now in the UK and elsewhere in Europe may be just the beginning of the epidemic; heterozygotes (like those in the current study) may have a longer incubation period for the disease. The authors suggest that:

Mean incubation periods of human BSE [bovine spongioform encephalopathy] infection of 30 years or more should therefore be regarded as possible, if not probable, with the longest incubation periods approaching (and perhaps exceeding) the typical human lifespan.

This conclusion is reached by extrapolating from kuru to human exposure to BSE, but it should be noted that there are some problems with this. First, kuru represents a human-to-human transmission event (dubbed "intraspecies recycling" in the paper). Studies of prions in a laboratory setting using animal models have shown that there is a species barrier to transmission, and that prions that have been adapted to a particular species--for example, prions that have been passaged once in a mouse, and are then harvested and inoculated into a second mouse--result in a decreased incubation period and a higher lethality when compared to the primary passage (which would have come from another animal species, such as a cow or human). Therefore, kuru may have a shorter incubation period and higher virulence than BSE transmitted to humans. Additionally, the concentration of prions varies by animal tissue. Kuru has been especially associated with handling or consumption of the host brain (high in prion concentration), whereas individuals exposed to BSE have been so via contaminated animal muscle (theoretically, with minimal nervous tissue involvement). Therefore, the infectious dose of the prion should be much lower for BSE than that in kuru, which may either extend the incubation period beyond even 30 years, or may mean that the theoretical "mad cow" epidemic will never materialize. Unfortunately, only time will tell.

Reference

Collinge et al. 2006. Kuru in the 21st century--an acquired human prion disease with very long incubation periods. Lancet. 367:2068-74.

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Investigations showed that the disease was spread by cannibalism ...

It's interesting, actually, how weak the evidence for cannibalism spreading the disease actually is. An alternative explanation is that people were infected through skin cuts during the funerary rites, and in fact at least with non-human primates kuru is far more infectious by injection than by the oral route. Gajdusek originally considered this possibility:

Natural transmission is believed to be related to the mourning rituals of the Fore people, which consisted of cannibalistic consumption of their dead relatives. Women and children who were engaged in the preparation of food could have becomes infected by selfinoculation through abrasions or cuts, or from nasal or conjunctival inoculation. In contrast to men, they also consumed the less well-cooked offal, including the brain; this could further account for the striking predominance of afflicted women and children of both sexes.

--P.W. Lampert, D.Carleton Gajdusek and Clarence J. Gibbs. Subacute
Spongiform Virus Encephalopathies. Scrapie, Kuru and Creutzfeldt-Jakob Disease: A Review. Am. J. Pathol. 68:630-645 (1972).
but later seemed to forget about it.

If you go way back and read the original papers on kuru by Gajdusek, there seems to be little if any actual evidence linking kuru to cannibalism -- in fact, in one of his earliest papers on the disease he explicitly rejects cannibalism as having a link, and lists a number of epidemiological and demographic reasons why:

There was no item of the Fore diet not also consumed in similar quantities by some neighboring kuru-free groups. Cannibalism, which included principally the consumption of kinsmen who had died of various causes, including kuru, by their close relatives, however, was more specifically a Fore trait than one of many of their neighbors. Early in the kuru investigation the possibility that cannibalism was involved in some hypersensitization or latent virus transmission was considered. However, neighbors such as the Tudahwe and Daribi near Kareimui and many other groups in New Guinea were likewise cannibal without suffering from kuru, and many of the younger kuru victims after 1958 were though never to have eaten dead relatives.

--D.Carleton Gajdusek. Slow-virus Infections of the Nervous System. New Engl. J. Med. 276:392-400 (1967)

Later, though, he switches to taking the cannibalism theory as a given, even though to the best of my knowledge no new data became available in the interim.

A third-party article (John D Matthews, Robert Glasse, and Shirley Lindenbaum. Kuru and Cannibalism. Lancet 2:449-452 (1968)) listed some reasons to suspect canniablism, and that's the only one I found that may have swayed Gajdusek -- but it's strange that some of the links those people claim as evidence, had been specifically raised and refuted in his earlier list.

One of the arguments that's supposed to have been proof that cannibalism caused kuru is that kuru was eliminated when cannibalism stopped -- but of course now that new kuru cases are turning up, that's not applicable.

I don't know that this changes the interpretation of the nvCJD risk particularly, but I jsut thought I'd throw it out.

You bring up a lot of interesting points. I've also read a bit of the literature regarding the importance (or lack thereof) of cannibalism in transmission, but they've been mainly summaries and reviews of the lit, so I'm not nearly as familiar with the original papers. A few notes, though.

Early in the kuru investigation the possibility that cannibalism was involved in some hypersensitization or latent virus transmission was considered. However, neighbors such as the Tudahwe and Daribi near Kareimui and many other groups in New Guinea were likewise cannibal without suffering from kuru...

This is pretty easily explained by noting that the misfolded protein simply may not have originated in any of the neighbors. Even in the Fore, it only would have had to originated once (and now that I think about it, I'm not sure if there's been any investigations into the source of the epidemic--did the prion originally come from another animal species that they ate? Was it a spontaneous case in a human, that was then passed along via funerary rites--either via cutting, or cannibalism? Anyhoo...) and then been passed among relatives and other mourners. As long as other neighboring tribes weren't involved in these rituals (even if they had their own), they could easily have stayed uninfected.

and many of the younger kuru victims after 1958 were though never to have eaten dead relatives.

I don't know enough about the research done to conclude these victims didn't partake of the feasts to really elaborate on this, but it's certainly possible that cannibalism isn't the only way this was spread. We know that in other prion diseases, prions can exist in milk and urine, and are very stable in the environment. It seems likely that consumption or accidental inoculation via preparation would provide the highest doses, but that doesn't mean other routes weren't involved as well. That also goes to your comment about skin cuts (which the authors do mention alongside cannibalism, though they don't focus on cuts).

One of the arguments that's supposed to have been proof that cannibalism caused kuru is that kuru was eliminated when cannibalism stopped -- but of course now that new kuru cases are turning up, that's not applicable.

Well, not quite. Even in this new paper, there weren't any cases in people who were born after cannibalism was outlawed; years of birth range from 1933 to 1949, so they would have had plenty of time to be exposed before the government cracked down on it. Had there been new cases in people born after 1960, that would be more difficult to account for, but none have been found (to my knowledge, anyway).

One might suppose that the taboos most have against cannibalism could have their roots in this kind of problem.

Did you hear about the cannibal who threw up his hands in disgust?

I'm fascinated by the fact that a prion appears to be a self-replicating entity without any of its own DNA-related components. Is it just an anomaly or is it a clue as to the chemical origins of life?

Two comments:

To BMurray: Prions are indeed fascinating and unique "entities" ("organisms" certainly wouldn't be appropriate), but I don't think they can be precisely described as "self-replicating." Since they simply impose their conformation on another preexisting protein of the same or similar sequence, rather than induce the de novo synthesis of a new protein, I don't think they really "self-replicate" in the way that the first hypothetical protein/ribozyme would presumably have.

Re the main article: I don't have access to the article itself, or most medical research at all at the moment, but I'm curious if the nvCJD incidence in Europe is rising or falling right now. From what I recall in the news, it was still rising in the late 1990s. They seem to be in the midst of the homozygote-portion of the epidemic right now, and the present trend should give us a hint at what part of the incidence over time curve we presently sit. From the kuru data, we would also anticipate a boomlet far into the future of heterozygotes, but it should be very much smaller and more diffuse than the homozygote boom, if it manifests at all.

HUMAN and ANIMAL TSE Classifications i.e. mad cow
disease and the UKBSEnvCJD only theory

TSEs have been rampant in the USA for decades in many
species, and they all have been rendered and fed back
to animals for human/animal consumption. I propose that
the current diagnostic criteria for human TSEs only
enhances and helps the spreading of human TSE from the
continued belief of the UKBSEnvCJD only theory in 2005.
With all the science to date refuting it, to continue
to validate this myth, will only spread this TSE agent
through a multitude of potential routes and sources
i.e. consumption, surgical, blood, medical, cosmetics
etc. I propose as with Aguzzi, Asante, Collinge,
Caughey, Deslys, Dormont, Gibbs, Ironside, Manuelidis,
Marsh, et al and many more, that the world of TSE
Tranmissible Spongiform Encephalopathy is far from an
exact science, but there is enough proven science to
date that this myth should be put to rest once and for
all, and that we move forward with a new classification
for human and animal TSE that would properly identify
the infected species, the source species, and then the
route. This would further have to be broken down to
strain of species and then the route of transmission
would further have to be broken down. Accumulation and
Transmission are key to the threshold from subclinical
to clinical disease. To continue with this myth that the U.K. strain of
BSE one strain in cows, and the nv/v CJD, one strain in
humans, and that all the rest of human TSE is one
single strain i.e. sporadic CJD (when to date there are
6 different phenotypes of sCJD), and that no other
animal TSE transmits to humans, to continue with this
masquerade will only continue to spread, expose, and
kill, who knows how many more in the years and decades
to come. ONE was enough for me, My Mom, hvCJD, DOD
12/14/97 confirmed, which is nothing more than another
mans name added to CJD, like CJD itself, Jakob and
Creutzfeldt, or Gerstmann-Straussler-Scheinker
syndrome, just another CJD or human TSE, named after
another human. WE are only kidding ourselves with the
current diagnostic criteria for human and animal TSE,
especially differentiating between the nvCJD vs the
sporadic CJD strains and then the GSS strains and also
the FFI fatal familial insomnia strains or the ones
that mimics one or the other of those TSE? Tissue
infectivity and strain typing of the many variants of
the human and animal TSEs are paramount in all variants
of all TSE. There must be a proper classification that
will differentiate between all these human TSE in order
to do this. With the CDI and other more sensitive
testing coming about, I only hope that my proposal will
some day be taken seriously.

My name is Terry S. Singeltary Sr. and I am no
scientist, no doctor and have no PhDs, but have been
independently researching human and animal TSEs since
the death of my Mother to the Heidenhain Variant of
Creutzfeldt Jakob Disease on December 14, 1997
'confirmed'. ...TSS

Subject: USDA, SPONTANEOUS MAD COW DISEASE, THE TOOTH FAIRY AND SANTA CLAUS
Date: June 12, 2006 at 5:18 am PST

IF we all believe the BSe that the USDA is trying to put out now about atypical BSE in USA cattle just arising spontaneously,
then we all should believe in the tooth fairy and santa claus as well.

IF USA scrapie transmitted to USA cattle long ago in experiments in a lab in Mission Texas did not produce UK BSE,
but something very different, then why would USA TSE cattle produce the UK human version of mad cow i.e. nvCJD?
IT wouldn't. USA sporadic cjd is increasing, the USA also has atypical human cases of unknown origin as well?

THERE are over 20 strains of scrapie, plus the atypical in sheep, and these strains are increasing in numbers.

SCRAPIE, CWD, AND TSE IN CATTLE i.e. ANIMAL TSE RAMPANT IN USA FOR DECADES, and amplified via rendering and
feeding practices, where USDA triple firewalls against BSE were nothing more than a mere smoke screen.

NO test tube TSE by either Prusiner or Soto, to date, have ever produced a TSE identical to the sporadic CJD. IN fact,
no test tube TSE has ever been produced that resembles _any_ natural field TSE.

IF you feed BSE tainted materials to cattle and primate, you have BSE and nvCJD.
IF you feed USA sheep strain to USA cattle, you get USA TSE.
IF you feed USA tainted cattle to humans, you get USA mad cow disease.
IF you feed sporadic CJD to primate you get a CJD infected primate.
NOTHING spontaneous about it at all.

USA is in a very unique situation. there are more documented TSE in different species than any other country,
all of which have been rendered and fed back to animals for human and animal consumption, for decades. Millions exposed,
and of these Millions, how many surgical and dental procedures have been done on these exposed, to pass on to others,
via the 'friendly fire' mode of transmission?

IF, the spontaneous TSE was true, then this would be Prusiner and everyone else that is trying to cash in on this agent with
there TSE rapid test, this would be there dream come true. IT would require mandatory BSE/TSE testing of all species,
due to the fact you could not ever eradicate it through any intervention. BUT, then again, the spontaneous TSE is like believing
in the tooth fairy or santa claus will be arriving at your house this year.

How long can this sharade continue $

How many more will become exposed and have to die $

Medical Sciences
Identification of a second bovine amyloidotic spongiform encephalopathy: Molecular similarities with sporadic Creutzfeldt-Jakob disease

Cristina Casalone *, Gianluigi Zanusso , Pierluigi Acutis *, Sergio Ferrari , Lorenzo Capucci , Fabrizio Tagliavini ¶, Salvatore Monaco ||, and Maria Caramelli *
*Centro di Referenza Nazionale per le Encefalopatie Animali, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna, 148, 10195 Turin, Italy; Department of Neurological and Visual Science, Section of Clinical Neurology, Policlinico G.B. Rossi, Piazzale L.A. Scuro, 10, 37134 Verona, Italy; Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Via Bianchi, 9, 25124 Brescia, Italy; and ¶Istituto Nazionale Neurologico "Carlo Besta," Via Celoria 11, 20133 Milan, Italy

Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved December 23, 2003 (received for review September 9, 2003)

Transmissible spongiform encephalopathies (TSEs), or prion diseases, are mammalian neurodegenerative disorders characterized by a posttranslational conversion and brain accumulation of an insoluble, protease-resistant isoform (PrPSc) of the host-encoded cellular prion protein (PrPC). Human and animal TSE agents exist as different phenotypes that can be biochemically differentiated on the basis of the molecular mass of the protease-resistant PrPSc fragments and the degree of glycosylation. Epidemiological, molecular, and transmission studies strongly suggest that the single strain of agent responsible for bovine spongiform encephalopathy (BSE) has infected humans, causing variant Creutzfeldt-Jakob disease. The unprecedented biological properties of the BSE agent, which circumvents the so-called "species barrier" between cattle and humans and adapts to different mammalian species, has raised considerable concern for human health. To date, it is unknown whether more than one strain might be responsible for cattle TSE or whether the BSE agent undergoes phenotypic variation after natural transmission. Here we provide evidence of a second cattle TSE. The disorder was pathologically characterized by the presence of PrP-immunopositive amyloid plaques, as opposed to the lack of amyloid deposition in typical BSE cases, and by a different pattern of regional distribution and topology of brain PrPSc accumulation. In addition, Western blot analysis showed a PrPSc type with predominance of the low molecular mass glycoform and a protease-resistant fragment of lower molecular mass than BSE-PrPSc. Strikingly, the molecular signature of this previously undescribed bovine PrPSc was similar to that encountered in a distinct subtype of sporadic Creutzfeldt-Jakob disease.

--------------------------------------------------------------------------------

C.C. and G.Z. contributed equally to this work.

||To whom correspondence should be addressed.

E-mail: salvatore.monaco@mail.univr.it.
www.pnas.org/cgi/doi/10.1073/pnas.0305777101

http://www.pnas.org/cgi/content/abstract/0305777101v1

: J Infect Dis 1980 Aug;142(2):205-8

Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.

Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.

Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.

PMID: 6997404

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&li…

Atypical cases of TSE in cases of TSE in
cattle and sheep cattle and sheep
H. De H. De Bosschere Bosschere
CODA/CERVA CODA/CERVA
Nat. Ref. Lab. Vet. Nat. Ref. Lab. Vet. TSEs TSEs
Belgium

http://www.var.fgov.be/pdf/1100_TSEDAY.pdf

USDA 2004 ENHANCED BSE SURVEILLANCE PROGRAM AND HOW NOT TO FIND BSE CASES (OFFICIAL DRAFT OIG REPORT)

snip...

CATTLE With CNS Symptoms Were NOT Always Tested

snip...

Between FYs 2002 and 2004, FSIS condemned 680 cattle of all ages due to CNS symptoms. About 357 of these could be classified as adult. We could validate that ONLY 162 were tested for BSE (per APHIS records. ...

snip...

WE interviewed officials at five laboratories that test for rabies. Those officials CONFIRMED THEY ARE NOT REQUIRED TO SUBMIT RABIES-NEGATIVE SAMPLES TO APHIS FOR BSE TESTING. A South Dakota laboratory official said they were not aware they could submit rabies-negative samples to APHIS for BSE testing. A laboratory official in another State said all rabies-negative cases were not submitted to APHIS because BSE was ''NOT ON THEIR RADAR SCREEN." Officials from New York, Wisconsin, TEXAS, and Iowa advised they would NOT submit samples from animals they consider too young. Four of the five States contacted defined this age as 24 months; Wisconsin defined it as 30 months. TEXAS officials also advised that they do not always have sufficient tissue remaining to submit a BSE sample. ...

snip...

FULL TEXT 54 PAGES OF HOW NOT TO FIND BSE IN USA ;

http://www.house.gov/reform/min/pdfs_108_2/pdfs_inves/pdf_food_usda_mad…

HUMAN TSE USA 2005

Animal Prion Diseases Relevant to Humans (unknown types?)
Thu Oct 27, 2005 12:05
71.248.128.109

About Human Prion Diseases /
Animal Prion Diseases Relevant to Humans

Bovine Spongiform Encephalopathy (BSE) is a prion
disease of cattle. Since 1986, when BSE was recognized,
over 180,000 cattle in the UK have developed the
disease, and approximately one to three million are
likely to have been infected with the BSE agent, most
of which were slaughtered for human consumption before
developing signs of the disease. The origin of the
first case of BSE is unknown, but the epidemic was
caused by the recycling of processed waste parts of
cattle, some of which were infected with the BSE agent
and given to other cattle in feed. Control measures
have resulted in the consistent decline of the epidemic
in the UK since 1992. Infected cattle and feed exported
from the UK have resulted in smaller epidemics in other
European countries, where control measures were applied
later.

Compelling evidence indicates that BSE can be
transmitted to humans through the consumption of prion
contaminated meat. BSE-infected individuals eventually
develop vCJD with an incubation time believed to be on
average 10 years. As of November 2004, three cases of
BSE have been reported in North America. One had been
imported to Canada from the UK, one was grown in
Canada, and one discovered in the USA but of Canadian
origin. There has been only one case of vCJD reported
in the USA, but the patient most likely acquired the
disease in the United Kingdom. If current control
measures intended to protect public and animal health
are well enforced, the cattle epidemic should be
largely under control and any remaining risk to humans
through beef consumption should be very small. (For
more details see Smith et al. British Medical Bulletin,
66: 185. 2003.)

Chronic Wasting Disease (CWD) is a prion disease of elk
and deer, both free range and in captivity. CWD is
endemic in areas of Colorado, Wyoming, and Nebraska,
but new foci of this disease have been detected in
Nebraska, South Dakota, New Mexico, Wisconsin,
Mississippi Kansas, Oklahoma, Minnesota, Montana, and
Canada. Since there are an estimated 22 million elk and
deer in the USA and a large number of hunters who
consume elk and deer meat, there is the possibility
that CWD can be transmitted from elk and deer to
humans. As of November 2004, the NPDPSC has examined 26
hunters with a suspected prion disease. However, all of
them appeared to have either typical sporadic or
familial forms of the disease. The NPDPSC coordinates
with the Centers for Disease Control and state health
departments to monitor cases from CWD-endemic areas.
Furthermore, it is doing experimental research on CWD
transmissibility using animal models. (For details see
Sigurdson et al. British Medical Bulletin. 66: 199.
2003 and Belay et al. Emerging Infectious Diseases.
10(6): 977. 2004.)

http://www.cjdsurveillance.com/abouthpd-animal.html

SEE STEADY INCREASE IN SPORADIC CJD IN THE USA FROM
1997 TO 2004. SPORADIC CJD CASES TRIPLED, and that is
with a human TSE surveillance system that is terrible
flawed. in 1997 cases of the _reported_ cases of cjd
were at 54, to 163 _reported_ cases in 2004. see stats
here;

p.s. please note the 47 PENDING CASES to Sept. 2005

p.s. please note the 2005 Prion D. total 120(8)
8=includes 51 type pending, 1 TYPE UNKNOWN ???

p.s. please note sporadic CJD 2002(1) 1=3 TYPE UNKNOWN???

p.s. please note 2004 prion disease (6) 6=7 TYPE
UNKNOWN???

http://www.cjdsurveillance.com/resources-casereport.html

CWD TO HUMANS = sCJD ???

AS implied in the Inset 25 we must not _ASSUME_ that
transmission of BSE to other species will invariably
present pathology typical of a scrapie-like disease.

snip...

http://www.bseinquiry.gov.uk/files/yb/1991/01/04004001.pdf

snip...end
full text ;

http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf

VERY VERY IMPORTANT THING TO REMEMBER

>> Differences in tissue distribution could require new regulations
>> regarding specific risk material (SRM) removal.

Research Project: Study of Atypical Bse

Location: Virus and Prion Diseases of Livestock

Project Number: 3625-32000-073-07
Project Type: Specific C/A

Start Date: Sep 15, 2004
End Date: Sep 14, 2007

Objective:
The objective of this cooperative research project with Dr. Maria Caramelli
from the Italian BSE Reference Laboratory in Turin, Italy, is to conduct
comparative studies with the U.S. bovine spongiform encephalopathy (BSE)
isolate and the atypical BSE isolates identified in Italy. The studies will
cover the following areas: 1. Evaluation of present diagnostics tools used
in the U.S. for the detection of atypical BSE cases. 2. Molecular comparison
of the U.S. BSE isolate and other typical BSE isolates with atypical BSE
cases. 3. Studies on transmissibility and tissue distribution of atypical
BSE isolates in cattle and other species.

Approach:
This project will be done as a Specific Cooperative Agreement with the
Italian BSE Reference Laboratory, Istituto Zooprofilattico Sperimentale del
Piemonte, in Turin, Italy. It is essential for the U.S. BSE surveillance
program to analyze the effectiveness of the U.S diagnostic tools for
detection of atypical cases of BSE. Molecular comparisons of the U.S. BSE
isolate with atypical BSE isolates will provide further characterization of
the U.S. BSE isolate. Transmission studies are already underway using brain
homogenates from atypical BSE cases into mice, cattle and sheep. It will be
critical to see whether the atypical BSE isolates behave similarly to
typical BSE isolates in terms of transmissibility and disease pathogenesis.
If transmission occurs, tissue distribution comparisons will be made between
cattle infected with the atypical BSE isolate and the U.S. BSE isolate.
Differences in tissue distribution could require new regulations regarding
specific risk material (SRM) removal.

http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=408490

3.57 The experiment which might have determined whether BSE and scrapie were
caused by the same agent (ie, the feeding of natural scrapie to cattle) was
never undertaken in the UK. It was, however, performed in the USA in 1979,
when it was shown that cattle inoculated with the scrapie agent endemic in
the flock of Suffolk sheep at the United States Department of Agriculture in
Mission, Texas, developed a TSE quite unlike BSE. 32 The findings of the
initial transmission, though not of the clinical or neurohistological
examination, were communicated in October 1988 to Dr Watson, Director of the
CVL, following a visit by Dr Wrathall, one of the project leaders in the
Pathology Department of the CVL, to the United States Department of
Agriculture. 33 The results were not published at this point, since the
attempted transmission to mice from the experimental cow brain had been
inconclusive. The results of the clinical and histological differences
between scrapie-affected sheep and cattle were published in 1995. Similar
studies in which cattle were inoculated intracerebrally with scrapie inocula
derived from a number of scrapie-affected sheep of different breeds and from
different States, were carried out at the US National Animal Disease Centre.
34 The results, published in 1994, showed that this source of scrapie agent,
though pathogenic for cattle, did not produce the same clinical signs of
brain lesions characteristic of BSE.

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm#820543

The findings of the initial transmission, though not of the clinical or
neurohistological examination, were communicated in October 1988 to Dr
Watson, Director of the CVL, following a visit by Dr Wrathall, one of the
project leaders in the Pathology Department of the CVL, to the United States
Department of Agriculture. 33

http://www.bseinquiry.gov.uk/files/yb/1988/10/00001001.pdf

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm#820546

The results were not published at this point, since the attempted
transmission to mice from the experimental cow brain had been inconclusive.
The results of the clinical and histological differences between
scrapie-affected sheep and cattle were published in 1995. Similar studies in
which cattle were inoculated intracerebrally with scrapie inocula derived
from a number of scrapie-affected sheep of different breeds and from
different States, were carried out at the US National Animal Disease Centre.
34 The
results, published in 1994, showed that this source of scrapie agent, though
pathogenic for cattle, did not produce the same clinical signs of brain
lesions characteristic of BSE.

3.58 There are several possible reasons why the experiment was not performed
in the UK. It had been recommended by Sir Richard Southwood (Chairman of the
Working Party on Bovine Spongiform Encephalopathy) in his letter to the
Permanent Secretary of MAFF, Mr (now Sir) Derek Andrews, on 21 June 1988, 35
though it was not specifically recommended in the Working Party Report or
indeed in the Tyrrell Committee Report (details of the Southwood Working
Party and the Tyrell Committee can be found in vol. 4: The Southwood Working
Party, 1988-89 and vol. 11: Scientists after Southwood respectively). The
direct inoculation of scrapie into calves was given low priority, because of
its high cost and because it was known that it had already taken place in
the USA. 36 It was also felt that the results of such an experiment would be
hard to interpret. While a negative result would be informative, a positive
result would need to demonstrate that when scrapie was transmitted to
cattle, the disease which developed in cattle was the same as BSE. 37 Given
the large number of strains of scrapie and the possibility that BSE was one
of them, it would be necessary to transmit every scrapie strain to cattle
separately, to test the hypothesis properly. Such an experiment would be
expensive. Secondly, as measures to control the epidemic took hold, the need
for the experiment from the policy viewpoint was not considered so urgent.
It was felt that the results would be mainly of academic interest. 38

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm#820550

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm

REPORT OF THE COMMITTEE ON SCRAPIE

Chair: Dr. Jim Logan, Cheyenne, WY

Vice Chair: Dr. Joe D. Ross, Sonora, TX

Dr. Deborah L. Brennan, MS; Dr. Beth Carlson, ND; Dr. John R. Clifford, DC; Dr. Thomas F. Conner, OH; Dr. Walter E. Cook, WY; Dr. Wayne E. Cunningham, CO; Dr. Jerry W. Diemer, TX; Dr. Anita J. Edmondson, CA; Dr. Dee Ellis, TX; Dr. Lisa A. Ferguson, MD; Dr. Keith R. Forbes, NY; Dr. R. David Glauer, OH; Dr. James R. Grady, CO; Dr. William L. Hartmann, MN; Dr. Carolyn Inch, CAN; Dr. Susan J. Keller, ND; Dr. Allen M. Knowles, TN; Dr. Thomas F. Linfield, MT; Dr. Michael R. Marshall, UT; Dr. Cheryl A. Miller, In; Dr. Brian V. Noland, CO; Dr. Charles Palmer, CA; Dr. Kristine R. Petrini, MN; Mr. Stan Potratz, IA; Mr. Paul E. Rodgers, CO; Dr. Joan D. Rowe, CA; Dr. Pamela L. Smith, IA; Dr. Diane L. Sutton, MD; Dr. Lynn Anne Tesar, SD; Dr. Delwin D. Wilmot, NE; Dr. Nora E. Wineland, CO; Dr. Cindy B. Wolf, MN.

The Committee met on November 9, 2005, from 8:00am until 11:55am, Hershey Lodge and Convention Center, Hershey, Pennsylvania. The meeting was called to order by Dr. Jim Logan, chair, with vice chairman Dr. Joe D. Ross attending. There were 74 people in attendance.

The Scrapie Program Update was provided by Dr. Diane Sutton, National Scrapie Program Coordinator, United States Department of Agriculture (USDA), Animal and Plant Health Inspection Services (APHIS), Veterinary Services (VS). The complete text of the Status Report is included in these Proceedings.

Dr. Patricia Meinhardt, USDA-APHIS-VS-National Veterinary Services Laboratory (NVSL) gave the Update on Genotyping Labs and Discrepancies in Results. NVSL conducts investigations into discrepancies on genotype testing results associated with the Scrapie Eradication Program. It is the policy of the Program to conduct a second genotype test at a second laboratory on certain individual animals. Occasionally, there are discrepancies in those results. The NVSL conducts follow-up on these situations through additional testing on additional samples from the field and archive samples from the testing laboratories.

For the period of time from January 1, 2005, until October 15, 2005, there were 23 instances of discrepancies in results from 35 flocks. Of those 23 instances, 14 were caused by laboratory error (paperwork or sample mix-up), 3 results from field error, 5 were not completely resolved, and 1 originated from the use of a non-approved laboratory for the first test. As a result of inconsistencies, one laboratory's certification was revoked by APHIS-VS.

snip...

Infected and Source Flocks

As of September 30, 2005, there were 105 scrapie infected and source flocks. There were a total of 165** new infected and source flocks reported for FY 2005. The total infected and source flocks that have been released in FY 2005 was 128. The ratio of infected and source flocks cleaned up or placed on clean up plans vs. new infected and source flocks discovered in FY 2005 was 1.03 : 1*. In addition 622 scrapie cases were confirmed and reported by the National Veterinary Services Laboratories (NVSL) in FY 2005, of which 130 were RSSS cases. Fifteen cases of scrapie in goats have been reported since 1990. The last goat case was reported in May 2005. Approximately 5,626 animals were indemnified comprised of 49% non-registered sheep, 45% registered sheep, 1.4% non-registered goats and 4.6% registered goats.

Regulatory Scrapie Slaughter Surveillance (RSSS)

RSSS was designed to utilize the findings of the Center for Epidemiology and Animal Health (CEAH) Scrapie: Ovine Slaughter Surveillance (SOSS) study. The results of SOSS can be found at http://www.aphis.usda.gov/vs/ceah/cahm/Sheep/sheep.htm . RSSS started April 1,

2003. It is a targeted slaughter surveillance program which is designed to identify infected flocks for clean-up. During FY 2005 collections increased by 32% overall and by 90% for black and mottled faced sheep improving overall program effectiveness and efficiency as demonstrated by the 26% decrease in percent positive black faced sheep compared to FY 2004. Samples have been collected from 62,864 sheep since April 1, 2003, of which results have been reported for 59,105 of which 209 were confirmed positive. During FY 2005, 33,137 samples were collected from 81 plants. There have been 130 NVSL confirmed positive cases (30 collected in FY 2004 and confirmed in FY 2005 and 100 collected and confirmed in FY 2005) in FY 2005. Face colors of these positives were 114 black, 14 mottled, 1 white and 1 unknown. The percent positive by face color is shown in the chart below.

Scrapie Testing

In FY 2005, 35,845 animals have been tested for scrapie: 30,192 RSSS; 4,742 regulatory field cases; 772 regulatory third eyelid biopsies; 10 third eyelid validations; and 129 necropsy validations (chart 9).

Animal ID

As of October 04, 2005, 103,580 sheep and goat premises have been assigned identification numbers in the Scrapie National Generic Database. Official eartags have been issued to 73,807 of these premises.

*This number based on an adjusted 12 month interval to accommodate the 60 day period for setting up flock plans.

http://www.usaha.org/committees/reports/2005/report-scr-2005.pdf

Date: April 30, 2006 at 4:49 pm PST
SCRAPIE USA UPDATE AS of March 31, 2006

2 NEW CASES IN GOAT, 82 INFECTED SOURCE FLOCKS, WITH 4 NEW INFECTED SOURCE
FLOCKS IN MARCH, WITH 19 SCRAPIE INFECTED RSSS REPORTED BY NVSL

http://www.aphis.usda.gov/vs/nahps/scrapie/monthly_report/monthly-repor…

Published online before print October 20, 2005

Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502296102
Medical Sciences

A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes

( sheep prion | transgenic mice )

Annick Le Dur *, Vincent Béringue *, Olivier Andréoletti , Fabienne Reine *, Thanh Lan Laï *, Thierry Baron , Bjørn Bratberg ¶, Jean-Luc Vilotte ||, Pierre Sarradin **, Sylvie L. Benestad ¶, and Hubert Laude *
*Virologie Immunologie Moléculaires and ||Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway

Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)

Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.

--------------------------------------------------------------------------------

Author contributions: H.L. designed research; A.L.D., V.B., O.A., F.R., T.L.L., J.-L.V., and H.L. performed research; T.B., B.B., P.S., and S.L.B. contributed new reagents/analytic tools; V.B., O.A., and H.L. analyzed data; and H.L. wrote the paper.

A.L.D. and V.B. contributed equally to this work.

To whom correspondence should be addressed.

Hubert Laude, E-mail: laude@jouy.inra.fr

www.pnas.org/cgi/doi/10.1073/pnas.0502296102

http://www.pnas.org/cgi/content/abstract/0502296102v1

12/10/76
AGRICULTURAL RESEARCH COUNCIL
REPORT OF THE ADVISORY COMMITTE ON SCRAPIE
Office Note
CHAIRMAN: PROFESSOR PETER WILDY

snip...

A The Present Position with respect to Scrapie
A] The Problem

Scrapie is a natural disease of sheep and goats. It is a slow
and inexorably progressive degenerative disorder of the nervous system
and it ia fatal. It is enzootic in the United Kingdom but not in all
countries.

The field problem has been reviewed by a MAFF working group
(ARC 35/77). It is difficult to assess the incidence in Britain for
a variety of reasons but the disease causes serious financial loss;
it is estimated that it cost Swaledale breeders alone $l.7 M during
the five years 1971-1975. A further inestimable loss arises from the
closure of certain export markets, in particular those of the United
States, to British sheep.

It is clear that scrapie in sheep is important commercially and
for that reason alone effective measures to control it should be
devised as quickly as possible.

Recently the question has again been brought up as to whether
scrapie is transmissible to man. This has followed reports that the
disease has been transmitted to primates. One particularly lurid
speculation (Gajdusek 1977) conjectures that the agents of scrapie,
kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of
mink are varieties of a single "virus". The U.S. Department of
Agriculture concluded that it could "no longer justify or permit
scrapie-blood line and scrapie-exposed sheep and goats to be processed
for human or animal food at slaughter or rendering plants" (ARC 84/77)"
The problem is emphasised by the finding that some strains of scrapie
produce lesions identical to the once which characterise the human
dementias"

Whether true or not. the hypothesis that these agents might be
transmissible to man raises two considerations. First, the safety
of laboratory personnel requires prompt attention. Second, action
such as the "scorched meat" policy of USDA makes the solution of the
acrapie problem urgent if the sheep industry is not to suffer
grievously.

snip...

76/10.12/4.6

http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf

Like lambs to the slaughter
31 March 2001
Debora MacKenzie
Magazine issue 2284
What if you can catch old-fashioned CJD by eating meat from a sheep infected
with scrapie?
FOUR years ago, Terry Singeltary watched his mother die horribly from a
degenerative brain disease. Doctors told him it was Alzheimer's, but
Singeltary was suspicious. The diagnosis didn't fit her violent symptoms,
and he demanded an autopsy. It showed she had died of sporadic
Creutzfeldt-Jakob disease.

Most doctors believe that sCJD is caused by a prion protein deforming by
chance into a killer. But Singeltary thinks otherwise. He is one of a number
of campaigners who say that some sCJD, like the variant CJD related to BSE,
is caused by eating meat from infected animals. Their suspicions have
focused on sheep carrying scrapie, a BSE-like disease that is widespread in
flocks across Europe and North America.

Now scientists in France have stumbled across new evidence that adds weight
to the campaigners' fears. To their complete surprise, the researchers found
that one strain of scrapie causes the same brain damage in ...

The complete article is 889 words long.

full text;

http://www.newscientist.com/article.ns?id=mg16922840.300

Neurobiology
Adaptation of the bovine spongiform encephalopathy agent to primates and
comparison with Creutzfeldt- Jakob disease: Implications for human health
Corinne Ida Lasmézas*,, Jean-Guy Fournier*, Virginie Nouvel*, Hermann Boe*,
DomÃnÃque Marcé*, François Lamoury*, Nicolas Kopp, Jean-Jacques Hauw§, James
Ironside¶, Moira Bruce, Dominique Dormont*, and Jean-Philippe Deslys*
* Commissariat à l'Energie Atomique, Service de Neurovirologie, Direction
des Sciences du Vivant/Département de Recherche Medicale, Centre de
Recherches du Service de Santé des Armées 60-68, Avenue du Général Leclerc,
BP 6, 92 265 Fontenay-aux-Roses Cedex, France; Hôpital Neurologique Pierre
Wertheimer, 59, Boulevard Pinel, 69003 Lyon, France; § Laboratoire de
Neuropathologie, Hôpital de la Salpêtrière, 83, Boulevard de l'Hôpital,
75013 Paris, France; ¶ Creutzfeldt-Jakob Disease Surveillance Unit, Western
General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; and
Institute for Animal Health, Neuropathogenesis Unit, West Mains Road,
Edinburgh EH9 3JF, United Kingdom

Edited by D. Carleton Gajdusek, Centre National de la Recherche
Scientifique, Gif-sur-Yvette, France, and approved December 7, 2000
(received for review October 16, 2000)

Abstract

There is substantial scientific evidence to support the notion that bovine
spongiform encephalopathy (BSE) has contaminated human beings, causing
variant Creutzfeldt-Jakob disease (vCJD). This disease has raised concerns
about the possibility of an iatrogenic secondary transmission to humans,
because the biological properties of the primate-adapted BSE agent are
unknown. We show that (i) BSE can be transmitted from primate to primate by
intravenous route in 25 months, and (ii) an iatrogenic transmission of vCJD
to humans could be readily recognized pathologically, whether it occurs by
the central or peripheral route. Strain typing in mice demonstrates that the
BSE agent adapts to macaques in the same way as it does to humans and
confirms that the BSE agent is responsible for vCJD not only in the United
Kingdom but also in France. The agent responsible for French iatrogenic
growth hormone-linked CJD taken as a control is very different from vCJD but
is similar to that found in one case of sporadic CJD and one sheep scrapie
isolate. These data will be key in identifying the origin of human cases of
prion disease, including accidental vCJD transmission, and could provide
bases for vCJD risk assessment.

http://www.pnas.org/cgi/content/full/041490898v1

USDA CWD PROGRAM

http://www.aphis.usda.gov/vs/nahps/cwd/

USDA CWD MAP (slow to update)

http://www.aphis.usda.gov/vs/nahps/cwd/cwd-distribution.html

DRAFT

WYOMING GAME AND FISH DEPARTMENT

CHRONIC WASTING DISEASE MANAGEMENT PLAN

February 17, 2006

snip...

5. Predicted population effects on free-ranging elk based on captive elk chronically exposed to the CWD prion.
Forty-three female elk calves were trapped at the National Elk Refuge and transported to Sybille in February 2002. Elk were housed in pens, assumed to be environmentally contaminated with the CWD prion. Elk will be held throughout their lifetimes. Elk dying will be examined and cause of death determined. From these data, it will should be possible to model free-ranging elk mortality and population dynamics under extreme circumstances of CWD prion exposure and transmission. As of December 2005 (46 months post capture), 11 of 43 elk have died due to CWD. This compares to 100% mortality in less than 25 months in elk orally inoculated with different dosages of the CWD prion.

REVISED DRAFT

http://gf.state.wy.us/downloads/pdf/CWD2005reviseddraft.pdf

Prions in Skeletal Muscles of Deer with Chronic Wasting Disease

Rachel C. Angers,1* Shawn R. Browning,1*â  Tanya S. Seward,2 Christina J.
Sigurdson,4⡠Michael W. Miller,5 Edward A. Hoover,4 Glenn C. Telling1,2,3§

1Department of Microbiology, Immunology and Molecular Genetics, 2Sanders
Brown Center on Aging, 3Department of Neurology, University of Kentucky,
Lexington, KY 40536, USA. 4Department of Microbiology, Immunology and
Pathology, Colorado State University, Fort Collins, CO 80523, USA. 5Colorado
Division of Wildlife, Wildlife Research Center, Fort Collins, CO 80526, USA.

*These authors contributed equally to this work.

â Present address: Department of Infectology, Scripps Research Institute,
5353 Parkside Drive, RF-2, Jupiter, Florida, 33458, USA.

â¡Present address: Institute of Neuropathology, University of Zurich,
Schmelzbergstrasse 12, 8091 Zurich, Switzerland.

§To whom correspondence should be addressed: E-mail: gtell2@uky.edu

Prions are transmissible proteinaceous agents of mammals that cause fatal
neurodegenerative diseases of the central nervous system (CNS). The presence
of infectivity in skeletal muscle of experimentally infected mice raised the
possibility that dietary exposure to prions might occur through meat
consumption (1). Chronic wasting disease (CWD), an enigmatic and contagious
prion disease of North American cervids, is of particular concern. The
emergence of CWD in an increasingly wide geographic area and the
interspecies transmission of bovine spongiform encephalopathy (BSE) to
humans as variant Creutzfeldt Jakob disease (vCJD) have raised concerns
about zoonotic transmission of CWD.

To test whether skeletal muscle of diseased cervids contained prion
infectivity, Tg(CerPrP)1536 mice (2) expressing cervid prion protein
(CerPrP), were inoculated intracerebrally with extracts prepared from the
semitendinosus/semimembranosus muscle group of CWD-affected mule deer or
from CWD-negative deer. The availability of CNS materials also afforded
direct comparisons of prion infectivity in skeletal muscle and brain. All
skeletal muscle extracts from CWD-affected deer induced progressive
neurological dysfunction in Tg(CerPrP)1536 mice with mean incubation times
ranging between 360 and ~490 d, whereas the incubation times of prions from
the CNS ranged from ~230 to 280 d (Table 1). For each inoculation group, the
diagnosis of prion disease was confirmed by the presence of PrPSc in the
brains of multiple infected Tg(CerPrP)1536 mice (see supporting online
material for examples). In contrast, skeletal muscle and brain material from
CWD-negative deer failed to induce disease in Tg(CerPrP)1536 mice (Table 1)
and PrPSc was not detected in the brains of sacrificed asymptomatic mice as
late as 523 d after inoculation (supporting online material).

Our results show that skeletal muscle as well as CNS tissue of deer with CWD
contains infectious prions. Similar analyses of skeletal muscle BSE-affected
cattle did not reveal high levels of prion infectivity (3). It will be
important to assess the cellular location of PrPSc in muscle. Notably, while
PrPSc has been detected in muscles of scrapie-affected sheep (4), previous
studies failed to detect PrPSc by immunohistochemical analysis of skeletal
muscle from deer with natural or experimental CWD (5, 6). Since the time of
disease onset is inversely proportional to prion dose (7), the longer
incubation times of prions from skeletal muscle extracts compared to matched
brain samples indicated that prion titers were lower in muscle than in CNS
where infectivity titers are known to reach high levels. Although possible
effects of CWD strains or strain mixtures on these incubation times cannot
be excluded, the variable 360 to ~490 d incubation times suggested a range
of prion titers in skeletal muscles of CWD-affected deer. Muscle prion
titers at the high end of the range produced the fastest incubation times
that were ~30% longer than the incubation times of prions from the CNS of
the same animal. Since all mice in each inoculation group developed disease,
prion titers in muscle samples producing the longest incubation times were
higher than the end point of the bioassay, defined as the infectious dose at
which half the inoculated mice develop disease. Studies are in progress to
accurately assess prion titers.

While the risk of exposure to CWD infectivity following consumption of
prions in muscle is mitigated by relatively inefficient prion transmission
via the oral route (8), these

results show that semitendinosus/semimembranosus muscle, which is likely to
be consumed by humans, is a significant source of prion infectivity. Humans
consuming or handling meat from CWD-infected deer are therefore at risk to
prion exposure.

References and Notes

1. P. J. Bosque et al., Proc. Natl. Acad. Sci. U.S.A. 99, 3812 (2002).

2. S. R. Browning et al., J. Virol. 78, 13345 (2004).

3. A. Buschmann, M. H. Groschup, J. Infect. Dis. 192, 934 (2005).

4. O. Andreoletti et al., Nat. Med. 10, 591 (2004).

5. T. R. Spraker et al., Vet. Pathol. 39, 110 (2002).

6. A. N. Hamir, J. M. Miller, R. C. Cutlip, Vet. Pathol. 41, 78 (2004).

7. S. B. Prusiner et al., Biochemistry 21, 4883 (1980).

8. M. Prinz et al., Am. J. Pathol. 162, 1103 (2003).

9. This work was supported by grants from the U.S. Public Health Service
2RO1 NS040334-04 from the National Institute of Neurological Disorders and
Stroke and N01-AI-25491 from the National Institute of Allergy and
Infectious Diseases.

Supporting Online Material

www.sciencemag.org/

Materials and Methods

Fig. S1

21 November 2005; accepted 13 January 2006 Published online 26 January 2006;
10.1126/science.1122864 Include this information when citing this paper.

Table 1. Incubation times following inoculation of Tg(CerPrP)1536 mice with
prions from skeletal muscle and brain samples of CWD-affected deer.

Inocula Incubation time, mean d ± SEM (n/n0)*

Skeletal muscle Brain

CWD-affected deer

H92 360 ± 2 d (6/6) 283 ± 7 d (6/6)

33968 367 ± 9 d (8/8) 278 ± 11 d (6/6)

5941 427 ± 18 d (7/7)

D10 483 ± 8 d (8/8) 231 ± 17 d (7/7)

D08 492 ± 4 d (7/7)

Averages 426 d 264 d

Non-diseased deer

FPS 6.98 >523 d (0/6)

FPS 9.98 >454 d (0/7) >454 d (0/6)

None >490 d (0/6)

PBS >589 d (0/5)

*The number of mice developing prion disease divided by the original number
of inoculated mice is shown in parentheses. Mice dying of intercurrent
illnesses were excluded.

http://www.sciencemag.org/

www.sciencemag.org/

Supporting Online Material for

Prions in Skeletal Muscles of Deer with Chronic Wasting Disease

Rachel C. Angers, Shawn R. Browning, Tanya S. Seward, Christina J.
Sigurdson,

Michael W. Miller, Edward A. Hoover, Glenn C. Telling§

§To whom correspondence should be addressed: E-mail: gtell2@uky.edu

Published 26 January 2006 on Science Express

DOI: 10.1126/science.1122864

This PDF file includes:

Materials and Methods

Fig. S1

Supporting Online Materials

Materials and Methods

Homogenates of semitendinosus/semimembranosus muscle (10% w/v in phosphate

buffered saline) were prepared from five emaciated and somnolent mule deer,
naturally

infected with CWD at the Colorado Division of Wildlife, Wildlife Research
Center.

These deer were identified as D10, D08, 33968, H92, and 5941. CWD infection
was

confirmed in all cases by the presence of histologic lesions in the brain
including

spongiform degeneration of the perikaryon, the immunohistochemical detection
of

disease-associated PrP in brain and tonsil, or by immunoblotting of
protease-resistant,

disease associated PrP (CerPrPSc). Semitendinosus/semimembranosus muscle was
also

obtained from two asymptomatic, mock inoculated deer, referred to as FPS
6.68 and 9.98,

that originated from a CWD non-endemic area and which were held indoors at
Colorado

State University from ten days of age. These control deer were confirmed
negative for

CWD by histopathological and immunohistochemical analysis of brain tissue at
autopsy.

The utmost care was taken to avoid inclusion of obvious nervous tissue when
muscle

biopsies were prepared and to ensure that contamination of skeletal muscle
samples with

CNS tissue did not occur. Fresh, single-use instruments were used to collect
each sample

biopsy and a central piece from each sample was prepared with fresh,
disposable

instruments to further isolate muscle tissue for inoculum preparation. Brain
samples for

transmission were prepared separately from muscle as additional insurance
against cross

contamination.

1

Groups of anesthetized Tg(CerPrP)1536 mice were inoculated intracerebrally
with 30 µl

of 1 % skeletal muscle or brain extracts prepared in phosphate buffered
saline (PBS).

Inoculated Tg(CerPrP) mice were diagnosed with prion disease following the
progressive

development of at least three neurologic symptoms including truncal ataxia,
'plastic' tail,

loss of extensor reflex, difficultly righting, and slowed movement. The time
from

inoculation to the onset of clinical signs is referred to as the incubation
time.

For PrP analysis in brain extracts of Tg(CerPrP)1536 mice, 10 % homogenates
prepared

in PBS were either untreated (-) or treated (+) with 40 µg/ml proteinase K
(PK) for one

hour at 37oC in the presence of 2% sarkosyl. Proteins were separated by
sodium dodecyl

sulfate polyacrylamide gel electrophoresis, analyzed by immunoblotting using
anti PrP

monoclonal antibody 6H4 (Prionics AG, Switzerland), incubated with
appropriate

secondary antibody, developed using ECL-plus detection (Amersham), and
analyzed

using a FLA-5000 scanner (Fuji).

2

Fig. S1

PrP in brain extracts from representative Tg(CerPrP)1536 mice receiving
muscle or CNS

tissue inocula from CWD-affected or CWD-negative deer. Extracts were either
treated

(+) or untreated (-) with proteinase K (PK) as indicated. The positions of
protein

molecular weight markers at 21.3, 28.7, 33.5 kDa (from bottom to top) are
shown to the

left of the immunoblot.

3

http://www.sciencemag.org/

Chronic Wasting Disease and Potential Transmission to Humans
Ermias D. Belay,* Ryan A. Maddox,* Elizabeth S. Williams,â  Michael W. Miller,â¡ Pierluigi Gambetti,§ and Lawrence B. Schonberger*
*Centers for Disease Control and Prevention, Atlanta, Georgia, USA; â University of Wyoming, Laramie, Wyoming, USA; â¡Colorado Division of Wildlife, Fort Collins, Colorado, USA; and §Case Western Reserve University, Cleveland, Ohio, USA

Suggested citation for this article: Belay ED, Maddox RA, Williams ES, Miller MW, Gambetti P, Schonberger LB. Chronic wasting disease and potential transmission to humans. Emerg Infect Dis [serial on the Internet]. 2004 Jun [date cited]. Available from: http://www.cdc.gov/ncidod/EID/vol10no6/03-1082.htm

http://www.cdc.gov/ncidod/EID/vol10no6/03-1082.htm

Research

Environmental Sources of Prion Transmission in Mule Deer
Michael W. Miller,* Elizabeth S. Williams,â  N. Thompson Hobbs,â¡ and Lisa L. Wolfe*
*Colorado Division of Wildlife, Fort Collins, Colorado, USA; â University of Wyoming, Laramie, Wyoming, USA; and â¡Colorado State University, Fort Collins, Colorado, USA

Suggested citation for this article: Miller MW, Williams ES, Hobbs NT, Wolfe LL. Environmental sources of prion transmission in mule deer. Emerg Infect Dis [serial on the Internet]. 2004 Jun [date cited]. Available from: http://www.cdc.gov/ncidod/EID/vol10no6/04-0010.htm

http://www.cdc.gov/ncidod/EID/vol10no6/04-0010.htm

ATYPICAL TSEs in USA CATTLE AND SHEEP ?

http://www.bseinquiry.gov.uk/files/sc/seac17/tab03.pdf

UKBSEnvCJD only theory Singeltary et al 2006
(please note, et al in this term means all victims and familes of the sporadic CJD
that are still looking for answers. ...TSS)

http://www.microbes.info/forums/index.php?act=Attach&type=post&id=13

http://www.microbes.info/forums/index.php?showtopic=306

NEW STRAIN OF TSE USA CATTLE OR JUST INCOMPETENCE IN TESTING???

http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-2.pdf

CJD WATCH

http://www.fortunecity.com/healthclub/cpr/349/part1cjd.htm

CJD WATCH MESSAGE BOARD

http://disc.server.com/Indices/167318.html

Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518

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Isn't there a possibility that the ban on cannibalism imposed by the Australians was not enforced properly, so that some of the Fore continued practicing the mortuary rituals?

Isn't there a possibility that the ban on cannibalism imposed by the Australians was not enforced properly, so that some of the Fore continued practicing the mortuary rituals?

I suppose anything's possible, but I don't know of any evidence to support that. Additionally, if that were the case, you'd expect to see cases in people born after the ban, and none have been reported to my knowledge.

>>>Re the main article: I don't have access to the article itself, or most medical research at all at the moment, but I'm curious if the nvCJD incidence in Europe is rising or falling right now. From what I recall in the news, it was still rising in the late 1990s. They seem to be in the midst of the homozygote-portion of the epidemic right now, and the present trend should give us a hint at what part of the incidence over time curve we presently sit. From the kuru data, we would also anticipate a boomlet far into the future of heterozygotes, but it should be very much smaller and more diffuse than the homozygote boom, if it manifests at all.<<<

for your reading........TSS

##################### Bovine Spongiform Encephalopathy #####################

further into this study;

Discussion

The early clinical, epidemiological, and anthropological study of kuru; the
recognition of its neuropathological, and then causal parallels to ovine
scrapie;20 and then crucially, the experimental transmission of the disease

to primates,21 originated the concept of the human transmissible spongiform
encephalopathies, which was followed in turn by the eventual unifying
concept of the mammalian prion diseases. However, in addition to the central
historical importance of kuru, study of the end-stage of this epidemic
offers a unique opportunity to study the variables of a near-complete
epidemic of human prion disease. In particular, recognition of the
incubation periods possible after natural prion infection in people is
important in providing an insight (from actual case histories rather than
from mathematical models) into the probable span of the vCJD epidemic in the
UK. Although estimation of kuru incubation periods early in the epidemic was
difficult, and the timing of the actual infecting event for an individual
can rarely be determined, the abrupt and permanent interruption of the
source of infection, endocannibalism, in the late 1950s, has progressively
allowed recognition of an enormous span of possible incubation periods, at
its shortest extreme bracketed by the rare onset of disease in children as
young as 5 years and extending up to (and perhaps beyond) the incubations
covering more than half a century, as we describe here.In our field studies,
we have interviewed many individuals who participated in traditional
mortuary feasting or who described the participation of family members from
the preceding generation. These detailed descriptions will be published
elsewhere but have reaffirmed the oral histories of endocannibalism in the
Fore recorded previously12,22-24 and that this practice ceased abruptly at
the time of Australian administrative control over the kuru areas. Although
isolated events might have occurred for a few years after this prohibition,
we are confident that new exposures of individuals to kuru at mortuary
feasts would not have occurred after 1960. Not only have no cases of kuru
been recorded in people born after 1959 (and only nine were recorded in
those born after 1956); but also all the 11 last recorded cases of kuru that
we report here were born before 1950. If any source of infection remained,
whether from surreptitious cannibalism, possible ground contam-ination with
human prions at sites where food was prepared, or other lateral routes, we
would expect individuals born after this period to have kuru--especially
since children are thought to have had shorter incubation periods than
adults. However, no such cases have been observed. Additionally, although a
fraction of hamster-adapted scrapie prions have been shown to survive in
soil for at least 3 years,25 the mortuary feast practices (during which the
entire body would be consumed) were undertaken so that any substantial
contamination of soil would not have occurred, and traditional bamboo knives
and leaf plates were burned after the feast. Furthermore, no clusters of
kuru cases, as seen earlier in the epidemic,26 have been recorded for many
years. We have also reviewed the assertion that maternal transmission of
kuru did not occur, and saw no evidence for maternal transmission from kuru
archives, interviews of colleagues who have practised medicine in the Fore,
or local oral history. Again, any possible vertical route of kuru
transmission would have resulted in the presence of kuru in children born
after 1960, especially since kuru was common in women of childbearing age;
no such cases have occurred.With respect to extrapolation of incubation
periods of BSE prion infection in people, we should recognise that the kuru
epidemic arose from intraspecies recycling of infectious prions. However,
transmission of prions between different mammalian species is associated
with a species barrier, which is better described as a transmission barrier,
because of the importance of within-species prion strain type, in addition
to species-specific differences in its determination.27 The biological
effects of such a barrier are: extended mean incubation period; increased
spread of incubation periods in individual animals; and reduced attack rate
(in which only a fraction of inoculated animals will succumb), by comparison
with the 100% mortality generally associated with within-species inoculation
with high-titre infectivity. Incubation periods approaching the natural
lifespan of the inoculated species are often seen in such primary
cross-species transmissions of prions. Second and subsequent passage of
prions within the new species is always associated with adaptation involving
a considerable shortening of the mean and spread of incubation periods and
high or total lethality to high-titre inocula. Thus, estimation of the range
of possible incubation periods in human BSE infection needs superimposition
of the effect of a transmission barrier onto these findings of natural human
incubation periods. The mean incubation period for kuru has been estimated
to be around 12 years,27 with a similar estimate in iatrogenic CJD
associated with the use of human-cadaver-derived pituitary growth hormone.28
As shown here, maximum incubation periods in kuru can exceed 50 years. The
transmission barrier of BSE between cattle and human beings is unknown and
cannot be directly measured. However, the cattle-to-mouse barrier for BSE
has been well characterised experimentally by comparative endpoint
titration. BSE prions transmit readily to laboratory mice, including after
oral dosing.29 The murine LD50 (lethal dose causing 50% mortality) in
C57Bl/6 mice is about 500-fold higher than that in cattle;30 this barrier
also results in a three-fold to four-fold increase in mean incubation
period.27 Mean incubation periods of human BSE infection of 30 years or more
should therefore be regarded as possible, if not probable,27 with the
longest incubation periods approaching (and perhaps exceeding) the typical
human lifespan. The shortest incubation periods in kuru were estimated from
the age of the youngest patients--suggesting that the shortest incubation
period was
Articles
www.thelancet.com Vol 367 June 24, 2006 2073
4-5 years. Similarly in vCJD, although the total clinical caseload so far
has been small, the youngest onsets of vCJD have been at age 12 years or
above, providing an early estimate of a minimum incubation period.
Furthermore, prion disease in mice follows a well-defined course with a
highly distinctive and repeatable incubation time for a specific prion
strain in a defined inbred mouse line. In addition to the PrP gene, a few
additional genetic loci with a major effect on incubation period have been
mapped.4,31,32 Human homologues of such loci could be important in human
susceptibility to prion disease, both after accidental human prion exposure
and after exposure to the BSE agent. By definition, patients identified so
far with vCJD are those with the shortest incubation periods for BSE. These
patients could have received an especially high dose of BSE prions. However,
no unusual history of dietary, occupational, or other exposure to BSE has
been reported from case-control studies. Because of the powerful genetic
effects on incubation period in laboratory animals, vCJD patients identified
could represent a distinct genetic subpopulation with unusually short
incubation periods to BSE prions, with vCJD so far occurring predominantly
in those individuals with short incubation time alleles at these multiple
genetic loci, in addition to having the homozygous PRNP genotype of codon
129 methionine. Therefore, a human BSE epidemic may be multiphasic, and
recent estimates of the size of the vCJD epidemic based on uniform genetic
susceptibility could be substantial underestimations.33,34 Genes implicated
in species-barrier effects, which would further increase both the mean and
range of human BSE incubation periods, are also probably relevant. In this
context, a human epidemic will be difficult to accurately model until such
modifier loci are identified and their gene frequencies in the population
can be measured.4Heterozygosity at PRNP codon 129 is a major determinant of
susceptibility to and incubation time of human prion diseases.5,7,9,35 As
expected, most of these recent kuru cases with extended incubation periods
(eight of ten) were heterozygotes. We have reported previously that most
elderly survivors of exposure to traditional mortuary feasts are
heterozygous.9 Although the study included a small number of patients with
kuru with long incubation periods, we saw no evidence of association with
PRNP haplotype,10 HLA-DQ7,18 APOE,36 or PRND alleles.13

Contributors

J Whitfield led the field patrol team throughout the study and investigated
all suspect cases; E McKintosh provided assistance during this time. J Beck
and S Mead undertook the molecular genetic studies. J Collinge, M P Alpers,
E McKintosh, and D J Thomas did field neurological examinations. J Collinge
and M P Alpers supervised the study and drafted the manuscript. All authors
contributed to and approved the final version of the manuscript. .........

snip...end...TSS

----- Original Message -----
From: "Terry S. Singeltary Sr."
To:
Sent: Thursday, June 22, 2006 7:48 PM
Subject: Kuru in the 21st century--an acquired human prion disea se

##################### Bovine Spongiform Encephalopathy
#####################

CJD WATCH MESSAGE BOARD
TSS
Kuru in the 21st century--an acquired human prion disease
Thu Jun 22, 2006 19:44
70.110.82.186

The Lancet 2006; 367:2068-2074

DOI:10.1016/S0140-6736(06)68930-7

Kuru in the 21st century--an acquired human prion disease with very long
incubation periods
John Collinge a , Jerome Whitfield a b, Edward McKintosh a, John Beck a,
Simon Mead a, Dafydd J Thomas a and Michael P Alpers a c

Summary
Background
Kuru provides the principal experience of epidemic human prion disease. Its
incidence has steadily fallen after the abrupt cessation of its route of
transmission (endocannibalism) in Papua New Guinea in the 1950s. The onset
of variant Creutzfeldt-Jakob disease (vCJD), and the unknown prevalence of
infection after the extensive dietary exposure to bovine spongiform
encephalopathy (BSE) prions in the UK, has led to renewed interest in kuru.
We investigated possible incubation periods, pathogenesis, and genetic
susceptibility factors in kuru patients in Papua New Guinea.

Methods
We strengthened active kuru surveillance in 1996 with an expanded field team
to investigate all suspected patients. Detailed histories of residence and
exposure to mortuary feasts were obtained together with serial neurological
examination, if possible.

Findings
We identified 11 patients with kuru from July, 1996, to June, 2004, all
living in the South Fore. All patients were born before the cessation of
cannibalism in the late 1950s. The minimum estimated incubation periods
ranged from 34 to 41 years. However, likely incubation periods in men ranged
from 39 to 56 years and could have been up to 7 years longer. PRNP analysis
showed that most patients with kuru were heterozygous at polymorphic codon
129, a genotype associated with extended incubation periods and resistance
to prion disease.

Interpretation
Incubation periods of infection with human prions can exceed 50 years. In
human infection with BSE prions, species-barrier effects, which are
characteristic of cross-species transmission, would be expected to further
increase the mean and range of incubation periods, compared with recycling
of prions within species. These data should inform attempts to model variant
CJD epidemiology.

Affiliations

a. MRC Prion Unit and Department of Neurodegenerative Disease, Institute of
Neurology, University College London, London WC1N 3BG, UK
b. Papua New Guinea Institute of Medical Research, Goroka, EHP, Papua New
Guinea
c. Centre for International Health, Curtin University, Perth, Australia

Correspondence to: Prof John Collinge

http://www.thelancet.com/journals/lancet/article/PIIS0140673606689307/a…

TSS

Listen to The Lancet
This week's audio summary discusses an Article entitled "Kuru in the 21st
century - an acquired human prion disease with very long incubation
periods". Also covered is a Lecture assessing climate change and its impact
on health, and an Editorial about the roll-out of cervical cancer vaccines
worldwide. >>

http://www.thelancet.com/webfiles/images/clusters/thelancet/audio/24Jun…

vCJD 'may develop over 50 years'

vCJD, like kuru, is a prion disease
A disease linked to cannibalism has given clues about how long mad cow
disease (BSE) can lurk in the human body before it develops into vCJD.

A University College London team said it could take 50 years for vCJD, the
human form of the disease, to develop.

They studied Papua New Guineans with a related condition - kuru disease,
which is contracted through cannibalism.

In The Lancet, the team said people with a certain genetic make-up risked
long-term vCJD incubation.

By investigating kuru, the only known example of a major epidemic of a prion
disease, we will begin to narrow our present uncertainties about vCJD

The Lancet

Exposure to BSE (bovine spongiform encephalopathy) in the UK has been
widespread, although just 160 vCJD (variant Creutzfeldt-Jakob) patients have
been identified, leading scientists to investigate why more people have not
been affected so far.

Kuru disease, like vCJD, is a prion disease. Prions are mutated proteins.

It reached epidemic proportions in some Papua New Guinea communities early
in the 20th Century.

Eating dead relatives as a mark of respect and mourning was ritual practice
until it was banned in the 1950s.

In the study, 11 patients with kuru were identified between July 1996 to
June 2004, with the last one born in 1959.

Although it was not possible to know the exact date the patients contracted
kuru, the possible incubation periods ranged from 34 to 56 years.

Genetic differences

The researchers believe the incubation period for BSE prions in humans could
be even longer than that seen in kuru because infection between different
species typically takes longer to develop than one passed within the same
species.

Professor John Collinge, who led the study, said vCJD patients identified so
far "could represent a distinct genetic subpopulation with unusually short
incubation periods for BSE".

He said a human BSE epidemic might have a number of phases, and added:
"Recent estimates of the size of the vCJD epidemic based on uniform genetic
susceptibility could be substantial underestimations."

An editorial in the Lancet stated: "The eventual size of the vCJD epidemic
remains uncertain.

"The number of infected individuals is still unknown.

"By investigating kuru, the only known example of a major epidemic of a
prion disease, we will begin to narrow our present uncertainties about vCJD.

"Any belief that vCJD incidence has peaked and that we are now through the
worst of this sinister disease must now be treated with extreme scepticism."

http://news.bbc.co.uk/1/hi/health/5106808.stm

TSS

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####################

#################### https://lists.aegee.org/bse-l.html ####################

CASES ARE RISING OF THE SPORADIC STRAIN IN THE UK AND IN OTHER COUNTRIES, AS IN THE USA WHERE IT HAS TRIPLED OVER RECENT YEARS, AND THE MOST DISTURBING FACTOR, THERE ARE ''UNKNOWN'' PHENOTYPES AND OR STRAINS I.E. ATYPICAL AS WITH THE LAST MAD COW IN TEXAS AND THE ONE IN ALABAMA, BOTH ATYPICAL TSE I.E. BASE HERE IS THE LATEST ON BASE CDC JUST PUT OUT, OF WHICH I BEEN TRYING TO WARN FOLKS FOR YEARS. ...TSS

Subject: Transmission of New Bovine Prion to Mice
Date: July 6, 2006 at 1:18 pm PST
Transmission of

New Bovine Prion

to Mice

Thierry G.M. Baron,* Anne-Gaëlle Biacabe,*

Anna Bencsik,* and Jan P.M. Langeveldâ 

We previously reported that cattle were affected by a

prion disorder that differed from bovine spongiform

encephalopathy (BSE) by showing distinct molecular features

of disease-associated protease-resistant prion protein

(PrPres). We show that intracerebral injection of such

isolates into C57BL/6 mice produces a disease with preservation

of PrPres molecular features distinct from BSE.

Until recently, transmissible spongiform encephalopathy

(TSE) in cattle was believed to be caused by a single

strain of infectious agent identified at the beginning of

a foodborne epidemic of bovine spongiform encephalopathy

(BSE). Characterization of the infectious agent associated

with BSE showed unique features. These include

defined incubation periods and distribution of brain lesions

after transmission to wild-type mice, not only directly

from cattle, but also after natural or experimentally

induced cross-species transmission (1,2). The uniform features

of the disease in cattle have also been shown by

analysis of the distribution of neurodegenerative brain

lesions at different places during the BSE epidemic (3,4).

Western blot analyses of protease-resistant prion protein

(PrPres) accumulating in the brains of animals and

humans with BSE have demonstrated specific molecular

features. These include a low molecular mass of unglycosylated

PrPres with high proportions of diglycosylated

PrPres (5,6). However, recent studies reported cases of

prion abnormalities in cattle with different PrPres features

(7,8). Three cattle isolates from France have been reported,

characterized by a higher apparent molecular mass of

unglycosylated PrPres (H-type isolates) and decreased levels

of diglycosylated PrPres when compared with BSE isolates

(7). In addition. only PrPres from H-type isolates were

labeled by monoclonal antibody P4 with defined PrPres N

terminus epitope specificity, in contrast with PrPres from

BSE isolates, which suggests a different cleavage by proteinase

K of the disease-associated protein (9).

Twenty years after identification of the BSE epidemic

in cattle, the origin of the BSE agent remains controversial

(10,11). Researchers have often considered the most

likely source to be a recycled infectious agent derived

from prion-associated diseases found in other species,

such as scrapie in sheep and goats. The recent description

of unusual phenotypes of bovine prion diseases distinct

from BSE is therefore puzzling (7). This situation has

been reinforced by a second bovine amyloidotic spongiform

encephalopathy found in cattle in Italy (8). However,

whether such cases of bovine prion disorders were transmissible,

and to what extent the infectious agent caused

specific features distinct from BSE, have not been

demonstrated.

The Study

Experimental groups of 20 (4- to 6-week old) C57BL/6

female mice (Charles River, L'Arbresle, France) were

injected intracerebrally with 20 µL of 10% (weight/volume)

homogenates per mouse prepared from brain stem

samples of 3 cattle TSE isolates. Two of the isolates were

characterized, as previously described (7), by a higher

molecular mass of unglycosylated PrPres (H-type isolates)

and labeling with P4 monoclonal antibody (Table). A typical

cattle BSE isolate was also analyzed. Mice were

housed and cared for in an appropriate biohazard prevention

area (A3) according to European (directive

86/609/EEC) and French ethical committee (decree

87-848) guidelines. Mice were checked at least weekly for

neurologic clinical signs and were killed when they exhibited

signs of distress or confirmed evolution of clinical

signs. The whole brain of every second mouse was frozen

and stored at -80°C before Western blot analysis. The

other brains were fixed in 4% paraformaldehyde for other

histopathologic studies.

Frozen mouse brain tissues and fixed brain tissues were

examined by Western blot analysis and immunohistochemical

tests as previously described (12,13). PrPres extracted

from half of whole brain was detected with monoclonal

antibodies Sha31 (1:10 from TeSeE sheep/goat Western

blot, Bio-Rad, Hercules, CA, USA) (14) and (340 ng/mL)

(15). These antibodies are directed against the 144-

WEDRYYRE-151 and 88-WGQGG-92 murine amino

acid PrP sequences, respectively. Antibody 12B2, which

has an N-terminal specificity similar to that of monoclonal

antibody P4, shows poor binding to BSE-derived PrPres,

but unlike P4, binds with high affinity to prion protein

from most mammalian species, including mice and cattle.

Bound antibodies were detected by using enhanced enzymatic

chemiluminescence (Amersham, Little Chalfont,

UK) or Supersignal (Pierce, Rockford, IL, USA) and visualized

either on film (Biomax, Eastman Kodak, Rochester,

NY, USA) or directly in an image analysis system

(Versadoc, Bio-Rad). Molecular masses of PrPres glycoforms

were determined as the average of the center positions

of the bands from at least 3 repeated electrophoretic

Emerging Infectious Diseases ⢠www.cdc.gov/eid ⢠Vol. 12, No. 7, July 2006 1125

*Agence Française de Sécurité Sanitaire des Aliments, Lyon,

France; and â Central Institute for Animal Disease Control,

Lelystad, the Netherlands

procedures, as measured by comparison with a biotinylated

marker (B2787, Sigma, Saint Louis, MO, USA)

included on each gel. Immunologic reactivities of antibodies

12B2 and Sha31 were compared in Western blots run in

parallel with the same samples with both antibodies.

After intracerebral injection of cattle brain samples into

C57BL/6 mice, disease was observed in mice with the 2 Htype

isolates, as well as with the BSE sample. Survival

periods of mice and results of PrPres detection among mice

analyzed by Western blot are shown in the Table.

Western blot analysis of PrPres from H-type-infected

mouse brains in comparison with BSE-infected mice is

shown in Figure 1. All positive mice in the same experimental

group showed the same Western blot pattern. This

pattern showed higher molecular mass PrPres glycoforms in

mice infected with H-type isolates than in mice infected

with a typical BSE agent (1.1- to 1.5-Da difference in the

unglycosylated PrPres (Figure 1A). Studies of PrPres protease

cleavage showed that only the PrPres of mice infected

with H-type isolates was recognized by antibody 12B2

(Figure 1B). This finding is in contrast to the result

obtained with monoclonal antibody Sha31 directed against

an epitope in the central region of the protein, which

showed that the 12B2 epitope was preserved in Htype-

infected mice. Thus, the molecular features of H-type

cattle isolates, which are distinct from those of the BSE

agent, were maintained after development of disease in

mice.

Histopathologic analysis showed vacuolar lesions in

the thalamus (Figure 2A) that were absent from the hypothalamus,

cochlear nucleus, and superior collicules. These

3 neuroanatomic sites were severely affected in C57BL/6

mice brain after primary passage of the BSE agent, as we

and others have reported (1). Abnormal PrP was detected

only in amyloid plaques (Figure 2B), in contrast to what

was reported after BSE transmission in C57BL/6 mice (1).

Conclusions

Our data show that the recently identified bovine Htype

isolates involve an infectious agent that can induce

development of a disease across a species barrier, while

maintaining the specific associated PrPres molecular signature.

This evidence in favor of a new bovine prion strain in

cattle suggests that BSE is not the only transmissible prion

disease in cattle. The origin of such cases has not been

determined (7). These cases suggest either the existence of

alternative origins of such diseases in cattle or phenotypic

changes of PrPres after infection with the BSE agent.

However, based on analysis of molecular features of prion

diseases in cattle, this situation is similar to that in humans

(5), in which different subtypes of sporadic Creutzfeldt-

Jakob disease agents are found.

DISPATCHES

1126 Emerging Infectious Diseases ⢠www.cdc.gov/eid ⢠Vol. 12, No. 7, July 2006

Figure 1. Western blot analysis of disease-associated prion protein

(PrPres) from proteinase K-treated brain homogenates of

C57BL/6 mice infected with type H (lanes 2 and 4) or bovine

spongiform encephalopathy isolates (lanes 3 and 5). PrPres of mice

infected with an experimental scrapie strain (C506M3) (6) was

used as a control (lane 1). Monoclonal antibodies used for detection

of PrPres were Sha31 in panel A and 12B2 in panel B. Lane M,

molecular mass markers: 39.8, 29, 20.1, and 14.3 kDa.

Acknowledgments

We thank Jérémy Verchère and Dominique Canal for excellent

technical assistance, Emilie Antier and Clément Lavigne for

performing animal experiments, and Karel Riepema, Esther de

Jong, and Jorg Jacobs for production and characterization of

monoclonal antibody 12B2.

This study was supported by the Agence Française de

Sécurité Sanitaire des Aliments, the Neuroprion Network of

Excellence (FOOD-CT-2004-506579) (EUROSTRAINS project),

the Dutch Ministry of Agriculture, Environmental

Management and Food (8041869000), and NeuroPrion (FOODCT-

2004-506579)(STOPPrions project).

Dr Baron is head of the Unité Agents Transmissibles Non

Conventionnels, Agence Française de Sécurité Sanitaire des

Aliments, in Lyon. His research focuses on diagnosis of prion

diseases of ruminants and characterization of the disease-associated

prion protein and infectious agents, with particular emphasis

on atypical forms of these diseases.

References

1. Fraser H, Bruce ME, Chree A, McConnell I, Wells GA. Transmission

of bovine spongiform encephalopathy and scrapie to mice. J Gen

Virol. 1992;73:1891-7.

2. Green R, Horrocks C, Wilkinson A, Hawkins SA, Ryder SJ. Primary

isolation of the bovine spongiform encephalopathy agent in mice:

agent definition based on a review of 150 transmissions. J Comp

Pathol. 2005;132:117-31.

3. Simmons MM, Harris P, Jeffrey M, Meek SC, Blamire IW, Wells GA.

BSE in Great Britain: consistency of the neurohistopathological findings

in two random annual samples of clinically suspect cases. Vet

Rec. 1996;138:175-7.

4. Orge L, Simas JP, Fernandes AC, Ramos M, Galo A. Similarity of the

lesion profile of BSE in Portuguese cattle to that described in British

cattle. Vet Rec. 2000;147:486-8.

5. Collinge J, Sidle KC, Meads J, Ironside J, Hill AF. Molecular analysis

of prion strain variation and the aetiology of 'new variant' CJD.

Nature. 1996;383:685-90.

6. Baron TG, Biacabe A-G. Molecular analysis of the abnormal prion

protein during coinfection of mice by bovine spongiform

encephalopathy and a scrapie agent. J Virol. 2001;75:107-14.

7. Biacabe A-G, Laplanche J-L, Baron L, Ryder SJ. Distinct molecular

phenotypes in bovine prion diseases. EMBO Rep. 2004;5:110-4.

8. Casalone C, Zanusso G, Acutis P, Ferrari S, Capucci L, Tagliavini F,

et al. Identification of a second bovine amyloidotic spongiform

encephalopathy: molecular similarities with sporadic Creutzfeldt-

Jakob disease. Proc Natl Acad Sci U S A. 2004;101:3065-70.

9. Thuring CM, Erkens JH, Jacobs JG, Bossers JG, van Keulen LJ,

Garssen GJ, et al. Discrimination between scrapie and bovine spongiform

encephalopathy in sheep by molecular size immunoreactivity

and glycoprofile of prion protein. J Clin Microbiol. 2004;42:972-80.

10. Marsh RF. Bovine spongiform encephalopathy: a new disease of cattle?

Arch Virol Suppl. 1993;7:255-9.

11. European Commission. Opinion on: hypotheses on the origin and

transmission of BSE. Brussels: EC Health and Consumer Protection

Directorate General; 2001. p. 1-67.

Transmission of New Bovine Prion to Mice

Emerging Infectious Diseases ⢠www.cdc.gov/eid ⢠Vol. 12, No. 7, July 2006 1127

Figure 2. Histopathologic analysis of brain of a C57BL/6 mouse

infected with a type H isolate. A) Characteristic vacuolar lesions in

the thalamus (hematoxylin and eosin stained, scale bar = 60 µm).

B) Immunohistochemical analysis of prion protein with monoclonal

antibody 12B2 (diluted 1:200) shows the absence of granular

deposition, but the presence of plaques in the thalamus. The inset

shows that plaques are amyloids since they bind Congo red and

show birefringence in polarized light (scale bar = 60 µm, scale bar

in inset = 16 µm).

12. Baron T, Crozet C, Biacabe A-G, Philippe S, Verchère J, Bencsik A,

et al. Molecular analysis of the protease-resistant prion protein in

scrapie and bovine spongiform encephalopathy transmitted to ovine

transgenic and wild-type mice. J Virol. 2004;78:6243-51.

13. Bencsik AA, Debeer S, Baron T. An alternative pretreatment procedure

in animal transmissible spongiform encephalopathies diagnosis

using PrPsc immunohistochemistry. J Histochem Cytochem.

2005;53:1199-202.

14. Feraudet C, Morel N, Simon S, Volland H, Frobert Y, Créminon C, et

al. Screening of 145 anti-PrP monoclonal antibodies for their capacity

to inhibit PrPsc replication in infected cells. J Biol Chem.

2005;280:11247-58.

15. Yull HM, Ritchie DL, Langeveld JP, van Zijderveld FG, Bruce ME,

Ironside JW, et al. Detection of type 1 prion protein in variant

Creutzfeldt-Jakob disease. Am J Pathol. 2006;168:151-7.

Address for correspondence: Thierry G.M. Baron, Unité Agents

Transmissibles Non Conventionnels, Agence Française de Sécurité

Sanitaire des Aliments, 31 Ave Tony Garnier, 69364 Lyon CEDEX 07,

France; email: t.baron@lyon.afssa.fr

http://www.cdc.gov/ncidod/EID/vol12no07/pdfs/vol12no07.pdf

Medical Sciences
Identification of a second bovine amyloidotic spongiform encephalopathy: Molecular similarities with sporadic Creutzfeldt-Jakob disease

Cristina Casalone *, Gianluigi Zanusso , Pierluigi Acutis *, Sergio Ferrari , Lorenzo Capucci , Fabrizio Tagliavini ¶, Salvatore Monaco ||, and Maria Caramelli *
*Centro di Referenza Nazionale per le Encefalopatie Animali, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna, 148, 10195 Turin, Italy; Department of Neurological and Visual Science, Section of Clinical Neurology, Policlinico G.B. Rossi, Piazzale L.A. Scuro, 10, 37134 Verona, Italy; Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Via Bianchi, 9, 25124 Brescia, Italy; and ¶Istituto Nazionale Neurologico "Carlo Besta," Via Celoria 11, 20133 Milan, Italy

Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved December 23, 2003 (received for review September 9, 2003)

Transmissible spongiform encephalopathies (TSEs), or prion diseases, are mammalian neurodegenerative disorders characterized by a posttranslational conversion and brain accumulation of an insoluble, protease-resistant isoform (PrPSc) of the host-encoded cellular prion protein (PrPC). Human and animal TSE agents exist as different phenotypes that can be biochemically differentiated on the basis of the molecular mass of the protease-resistant PrPSc fragments and the degree of glycosylation. Epidemiological, molecular, and transmission studies strongly suggest that the single strain of agent responsible for bovine spongiform encephalopathy (BSE) has infected humans, causing variant Creutzfeldt-Jakob disease. The unprecedented biological properties of the BSE agent, which circumvents the so-called "species barrier" between cattle and humans and adapts to different mammalian species, has raised considerable concern for human health. To date, it is unknown whether more than one strain might be responsible for cattle TSE or whether the BSE agent undergoes phenotypic variation after natural transmission. Here we provide evidence of a second cattle TSE. The disorder was pathologically characterized by the presence of PrP-immunopositive amyloid plaques, as opposed to the lack of amyloid deposition in typical BSE cases, and by a different pattern of regional distribution and topology of brain PrPSc accumulation. In addition, Western blot analysis showed a PrPSc type with predominance of the low molecular mass glycoform and a protease-resistant fragment of lower molecular mass than BSE-PrPSc. Strikingly, the molecular signature of this previously undescribed bovine PrPSc was similar to that encountered in a distinct subtype of sporadic Creutzfeldt-Jakob disease.

--------------------------------------------------------------------------------

C.C. and G.Z. contributed equally to this work.

||To whom correspondence should be addressed.

E-mail: salvatore.monaco@mail.univr.it.
www.pnas.org/cgi/doi/10.1073/pnas.0305777101

http://www.pnas.org/cgi/content/abstract/0305777101v1

TSS

#################### https://lists.aegee.org/bse-l.html ####################

USDA 2004 ENHANCED BSE SURVEILLANCE PROGRAM AND HOW NOT TO FIND BSE CASES
(OFFICIAL DRAFT OIG REPORT)

snip...

CATTLE With CNS Symptoms Were NOT Always Tested

snip...

Between FYs 2002 and 2004, FSIS condemned 680 cattle of all ages due to CNS
symptoms. About 357 of these could be classified as adult. We could validate
that ONLY 162 were tested for BSE (per APHIS records. ...

snip...

WE interviewed officials at five laboratories that test for rabies. Those
officials CONFIRMED THEY ARE NOT REQUIRED TO SUBMIT RABIES-NEGATIVE SAMPLES
TO APHIS FOR BSE TESTING. A South Dakota laboratory official said they were
not aware they could submit rabies-negative samples to APHIS for BSE
testing. A laboratory official in another State said all rabies-negative
cases were not submitted to APHIS because BSE was ''NOT ON THEIR RADAR
SCREEN." Officials from New York, Wisconsin, TEXAS, and Iowa advised they
would NOT submit samples from animals they consider too young. Four of the
five States contacted defined this age as 24 months; Wisconsin defined it as
30 months. TEXAS officials also advised that they do not always have
sufficient tissue remaining to submit a BSE sample. ...

snip...

FULL TEXT 54 PAGES OF HOW NOT TO FIND BSE IN USA ;

http://www.house.gov/reform/min/pdfs_108_2/pdfs_inves/pdf_food_usda_mad…

HUMAN TSE USA 2005

Animal Prion Diseases Relevant to Humans (unknown types?)
Thu Oct 27, 2005 12:05
71.248.128.109

About Human Prion Diseases /
Animal Prion Diseases Relevant to Humans

Bovine Spongiform Encephalopathy (BSE) is a prion
disease of cattle. Since 1986, when BSE was recognized,
over 180,000 cattle in the UK have developed the
disease, and approximately one to three million are
likely to have been infected with the BSE agent, most
of which were slaughtered for human consumption before
developing signs of the disease. The origin of the
first case of BSE is unknown, but the epidemic was
caused by the recycling of processed waste parts of
cattle, some of which were infected with the BSE agent
and given to other cattle in feed. Control measures
have resulted in the consistent decline of the epidemic
in the UK since 1992. Infected cattle and feed exported
from the UK have resulted in smaller epidemics in other
European countries, where control measures were applied
later.

Compelling evidence indicates that BSE can be
transmitted to humans through the consumption of prion
contaminated meat. BSE-infected individuals eventually
develop vCJD with an incubation time believed to be on
average 10 years. As of November 2004, three cases of
BSE have been reported in North America. One had been
imported to Canada from the UK, one was grown in
Canada, and one discovered in the USA but of Canadian
origin. There has been only one case of vCJD reported
in the USA, but the patient most likely acquired the
disease in the United Kingdom. If current control
measures intended to protect public and animal health
are well enforced, the cattle epidemic should be
largely under control and any remaining risk to humans
through beef consumption should be very small. (For
more details see Smith et al. British Medical Bulletin,
66: 185. 2003.)

Chronic Wasting Disease (CWD) is a prion disease of elk
and deer, both free range and in captivity. CWD is
endemic in areas of Colorado, Wyoming, and Nebraska,
but new foci of this disease have been detected in
Nebraska, South Dakota, New Mexico, Wisconsin,
Mississippi Kansas, Oklahoma, Minnesota, Montana, and
Canada. Since there are an estimated 22 million elk and
deer in the USA and a large number of hunters who
consume elk and deer meat, there is the possibility
that CWD can be transmitted from elk and deer to
humans. As of November 2004, the NPDPSC has examined 26
hunters with a suspected prion disease. However, all of
them appeared to have either typical sporadic or
familial forms of the disease. The NPDPSC coordinates
with the Centers for Disease Control and state health
departments to monitor cases from CWD-endemic areas.
Furthermore, it is doing experimental research on CWD
transmissibility using animal models. (For details see
Sigurdson et al. British Medical Bulletin. 66: 199.
2003 and Belay et al. Emerging Infectious Diseases.
10(6): 977. 2004.)

http://www.cjdsurveillance.com/abouthpd-animal.html

SEE STEADY INCREASE IN SPORADIC CJD IN THE USA FROM
1997 TO 2004. SPORADIC CJD CASES TRIPLED, and that is
with a human TSE surveillance system that is terrible
flawed. in 1997 cases of the _reported_ cases of cjd
were at 54, to 163 _reported_ cases in 2004. see stats
here;

p.s. please note the 47 PENDING CASES to Sept. 2005

p.s. please note the 2005 Prion D. total 120(8)
8=includes 51 type pending, 1 TYPE UNKNOWN ???

p.s. please note sporadic CJD 2002(1) 1=3 TYPE UNKNOWN???

p.s. please note 2004 prion disease (6) 6=7 TYPE
UNKNOWN???

http://www.cjdsurveillance.com/resources-casereport.html

CWD TO HUMANS = sCJD ???

AS implied in the Inset 25 we must not _ASSUME_ that
transmission of BSE to other species will invariably
present pathology typical of a scrapie-like disease.

snip...

http://www.bseinquiry.gov.uk/files/yb/1991/01/04004001.pdf

snip...end
full text ;

http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf

VERY VERY IMPORTANT THING TO REMEMBER

>> Differences in tissue distribution could require new regulations
>> regarding specific risk material (SRM) removal.

Research Project: Study of Atypical Bse

Location: Virus and Prion Diseases of Livestock

Project Number: 3625-32000-073-07
Project Type: Specific C/A

Start Date: Sep 15, 2004
End Date: Sep 14, 2007

Objective:
The objective of this cooperative research project with Dr. Maria Caramelli
from the Italian BSE Reference Laboratory in Turin, Italy, is to conduct
comparative studies with the U.S. bovine spongiform encephalopathy (BSE)
isolate and the atypical BSE isolates identified in Italy. The studies will
cover the following areas: 1. Evaluation of present diagnostics tools used
in the U.S. for the detection of atypical BSE cases. 2. Molecular comparison
of the U.S. BSE isolate and other typical BSE isolates with atypical BSE
cases. 3. Studies on transmissibility and tissue distribution of atypical
BSE isolates in cattle and other species.

Approach:
This project will be done as a Specific Cooperative Agreement with the
Italian BSE Reference Laboratory, Istituto Zooprofilattico Sperimentale del
Piemonte, in Turin, Italy. It is essential for the U.S. BSE surveillance
program to analyze the effectiveness of the U.S diagnostic tools for
detection of atypical cases of BSE. Molecular comparisons of the U.S. BSE
isolate with atypical BSE isolates will provide further characterization of
the U.S. BSE isolate. Transmission studies are already underway using brain
homogenates from atypical BSE cases into mice, cattle and sheep. It will be
critical to see whether the atypical BSE isolates behave similarly to
typical BSE isolates in terms of transmissibility and disease pathogenesis.
If transmission occurs, tissue distribution comparisons will be made between
cattle infected with the atypical BSE isolate and the U.S. BSE isolate.
Differences in tissue distribution could require new regulations regarding
specific risk material (SRM) removal.

http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=408490

3.57 The experiment which might have determined whether BSE and scrapie were
caused by the same agent (ie, the feeding of natural scrapie to cattle) was
never undertaken in the UK. It was, however, performed in the USA in 1979,
when it was shown that cattle inoculated with the scrapie agent endemic in
the flock of Suffolk sheep at the United States Department of Agriculture in
Mission, Texas, developed a TSE quite unlike BSE. 32 The findings of the
initial transmission, though not of the clinical or neurohistological
examination, were communicated in October 1988 to Dr Watson, Director of the
CVL, following a visit by Dr Wrathall, one of the project leaders in the
Pathology Department of the CVL, to the United States Department of
Agriculture. 33 The results were not published at this point, since the
attempted transmission to mice from the experimental cow brain had been
inconclusive. The results of the clinical and histological differences
between scrapie-affected sheep and cattle were published in 1995. Similar
studies in which cattle were inoculated intracerebrally with scrapie inocula
derived from a number of scrapie-affected sheep of different breeds and from
different States, were carried out at the US National Animal Disease Centre.
34 The results, published in 1994, showed that this source of scrapie agent,
though pathogenic for cattle, did not produce the same clinical signs of
brain lesions characteristic of BSE.

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm#820543

The findings of the initial transmission, though not of the clinical or
neurohistological examination, were communicated in October 1988 to Dr
Watson, Director of the CVL, following a visit by Dr Wrathall, one of the
project leaders in the Pathology Department of the CVL, to the United States
Department of Agriculture. 33

http://www.bseinquiry.gov.uk/files/yb/1988/10/00001001.pdf

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm#820546

The results were not published at this point, since the attempted
transmission to mice from the experimental cow brain had been inconclusive.
The results of the clinical and histological differences between
scrapie-affected sheep and cattle were published in 1995. Similar studies in
which cattle were inoculated intracerebrally with scrapie inocula derived
from a number of scrapie-affected sheep of different breeds and from
different States, were carried out at the US National Animal Disease Centre.
34 The
results, published in 1994, showed that this source of scrapie agent, though
pathogenic for cattle, did not produce the same clinical signs of brain
lesions characteristic of BSE.

3.58 There are several possible reasons why the experiment was not performed
in the UK. It had been recommended by Sir Richard Southwood (Chairman of the
Working Party on Bovine Spongiform Encephalopathy) in his letter to the
Permanent Secretary of MAFF, Mr (now Sir) Derek Andrews, on 21 June 1988, 35
though it was not specifically recommended in the Working Party Report or
indeed in the Tyrrell Committee Report (details of the Southwood Working
Party and the Tyrell Committee can be found in vol. 4: The Southwood Working
Party, 1988-89 and vol. 11: Scientists after Southwood respectively). The
direct inoculation of scrapie into calves was given low priority, because of
its high cost and because it was known that it had already taken place in
the USA. 36 It was also felt that the results of such an experiment would be
hard to interpret. While a negative result would be informative, a positive
result would need to demonstrate that when scrapie was transmitted to
cattle, the disease which developed in cattle was the same as BSE. 37 Given
the large number of strains of scrapie and the possibility that BSE was one
of them, it would be necessary to transmit every scrapie strain to cattle
separately, to test the hypothesis properly. Such an experiment would be
expensive. Secondly, as measures to control the epidemic took hold, the need
for the experiment from the policy viewpoint was not considered so urgent.
It was felt that the results would be mainly of academic interest. 38

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm#820550

http://www.bseinquiry.gov.uk/report/volume2/chaptea3.htm

REPORT OF THE COMMITTEE ON SCRAPIE

Chair: Dr. Jim Logan, Cheyenne, WY

Vice Chair: Dr. Joe D. Ross, Sonora, TX

Dr. Deborah L. Brennan, MS; Dr. Beth Carlson, ND; Dr. John R. Clifford, DC;
Dr. Thomas F. Conner, OH; Dr. Walter E. Cook, WY; Dr. Wayne E. Cunningham,
CO; Dr. Jerry W. Diemer, TX; Dr. Anita J. Edmondson, CA; Dr. Dee Ellis, TX;
Dr. Lisa A. Ferguson, MD; Dr. Keith R. Forbes, NY; Dr. R. David Glauer, OH;
Dr. James R. Grady, CO; Dr. William L. Hartmann, MN; Dr. Carolyn Inch, CAN;
Dr. Susan J. Keller, ND; Dr. Allen M. Knowles, TN; Dr. Thomas F. Linfield,
MT; Dr. Michael R. Marshall, UT; Dr. Cheryl A. Miller, In; Dr. Brian V.
Noland, CO; Dr. Charles Palmer, CA; Dr. Kristine R. Petrini, MN; Mr. Stan
Potratz, IA; Mr. Paul E. Rodgers, CO; Dr. Joan D. Rowe, CA; Dr. Pamela L.
Smith, IA; Dr. Diane L. Sutton, MD; Dr. Lynn Anne Tesar, SD; Dr. Delwin D.
Wilmot, NE; Dr. Nora E. Wineland, CO; Dr. Cindy B. Wolf, MN.

The Committee met on November 9, 2005, from 8:00am until 11:55am, Hershey
Lodge and Convention Center, Hershey, Pennsylvania. The meeting was called
to order by Dr. Jim Logan, chair, with vice chairman Dr. Joe D. Ross
attending. There were 74 people in attendance.

The Scrapie Program Update was provided by Dr. Diane Sutton, National
Scrapie Program Coordinator, United States Department of Agriculture (USDA),
Animal and Plant Health Inspection Services (APHIS), Veterinary Services
(VS). The complete text of the Status Report is included in these
Proceedings.

Dr. Patricia Meinhardt, USDA-APHIS-VS-National Veterinary Services
Laboratory (NVSL) gave the Update on Genotyping Labs and Discrepancies in
Results. NVSL conducts investigations into discrepancies on genotype testing
results associated with the Scrapie Eradication Program. It is the policy of
the Program to conduct a second genotype test at a second laboratory on
certain individual animals. Occasionally, there are discrepancies in those
results. The NVSL conducts follow-up on these situations through additional
testing on additional samples from the field and archive samples from the
testing laboratories.

For the period of time from January 1, 2005, until October 15, 2005, there
were 23 instances of discrepancies in results from 35 flocks. Of those 23
instances, 14 were caused by laboratory error (paperwork or sample mix-up),
3 results from field error, 5 were not completely resolved, and 1 originated
from the use of a non-approved laboratory for the first test. As a result of
inconsistencies, one laboratory's certification was revoked by APHIS-VS.

snip...

Infected and Source Flocks

As of September 30, 2005, there were 105 scrapie infected and source flocks.
There were a total of 165** new infected and source flocks reported for FY
2005. The total infected and source flocks that have been released in FY
2005 was 128. The ratio of infected and source flocks cleaned up or placed
on clean up plans vs. new infected and source flocks discovered in FY 2005
was 1.03 : 1*. In addition 622 scrapie cases were confirmed and reported by
the National Veterinary Services Laboratories (NVSL) in FY 2005, of which
130 were RSSS cases. Fifteen cases of scrapie in goats have been reported
since 1990. The last goat case was reported in May 2005. Approximately 5,626
animals were indemnified comprised of 49% non-registered sheep, 45%
registered sheep, 1.4% non-registered goats and 4.6% registered goats.

Regulatory Scrapie Slaughter Surveillance (RSSS)

RSSS was designed to utilize the findings of the Center for Epidemiology and
Animal Health (CEAH) Scrapie: Ovine Slaughter Surveillance (SOSS) study. The
results of SOSS can be found at
http://www.aphis.usda.gov/vs/ceah/cahm/Sheep/sheep.htm . RSSS started April
1,

2003. It is a targeted slaughter surveillance program which is designed to
identify infected flocks for clean-up. During FY 2005 collections increased
by 32% overall and by 90% for black and mottled faced sheep improving
overall program effectiveness and efficiency as demonstrated by the 26%
decrease in percent positive black faced sheep compared to FY 2004. Samples
have been collected from 62,864 sheep since April 1, 2003, of which results
have been reported for 59,105 of which 209 were confirmed positive. During
FY 2005, 33,137 samples were collected from 81 plants. There have been 130
NVSL confirmed positive cases (30 collected in FY 2004 and confirmed in FY
2005 and 100 collected and confirmed in FY 2005) in FY 2005. Face colors of
these positives were 114 black, 14 mottled, 1 white and 1 unknown. The
percent positive by face color is shown in the chart below.

Scrapie Testing

In FY 2005, 35,845 animals have been tested for scrapie: 30,192 RSSS; 4,742
regulatory field cases; 772 regulatory third eyelid biopsies; 10 third
eyelid validations; and 129 necropsy validations (chart 9).

Animal ID

As of October 04, 2005, 103,580 sheep and goat premises have been assigned
identification numbers in the Scrapie National Generic Database. Official
eartags have been issued to 73,807 of these premises.

*This number based on an adjusted 12 month interval to accommodate the 60
day period for setting up flock plans.

http://www.usaha.org/committees/reports/2005/report-scr-2005.pdf

Date: April 30, 2006 at 4:49 pm PST
SCRAPIE USA UPDATE AS of March 31, 2006

2 NEW CASES IN GOAT, 82 INFECTED SOURCE FLOCKS, WITH 4 NEW INFECTED SOURCE
FLOCKS IN MARCH, WITH 19 SCRAPIE INFECTED RSSS REPORTED BY NVSL

http://www.aphis.usda.gov/vs/nahps/scrapie/monthly_report/monthly-repor…

Published online before print October 20, 2005

Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502296102
Medical Sciences

A newly identified type of scrapie agent can naturally infect sheep with
resistant PrP genotypes

( sheep prion | transgenic mice )

Annick Le Dur *, Vincent Béringue *, Olivier Andréoletti , Fabienne Reine *,
Thanh Lan Laï *, Thierry Baron , Bjørn Bratberg ¶, Jean-Luc Vilotte ||,
Pierre Sarradin **, Sylvie L. Benestad ¶, and Hubert Laude *
*Virologie Immunologie Moléculaires and ||Génétique Biochimique et
Cytogénétique, Institut National de la Recherche Agronomique, 78350
Jouy-en-Josas, France; Unité Mixte de Recherche, Institut National de la
Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions
Hôte Agent Pathogène, 31066 Toulouse, France; Agence Française de Sécurité
Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels,
69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut
National de la Recherche Agronomique, 37380 Nouzilly, France; and
¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway

Edited by Stanley B. Prusiner, University of California, San Francisco, CA,
and approved September 12, 2005 (received for review March 21, 2005)

Scrapie in small ruminants belongs to transmissible spongiform
encephalopathies (TSEs), or prion diseases, a family of fatal
neurodegenerative disorders that affect humans and animals and can transmit
within and between species by ingestion or inoculation. Conversion of the
host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a
misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission
and pathogenesis. The intensified surveillance of scrapie in the European
Union, together with the improvement of PrPSc detection techniques, has led
to the discovery of a growing number of so-called atypical scrapie cases.
These include clinical Nor98 cases first identified in Norwegian sheep on
the basis of unusual pathological and PrPSc molecular features and "cases"
that produced discordant responses in the rapid tests currently applied to
the large-scale random screening of slaughtered or fallen animals.
Worryingly, a substantial proportion of such cases involved sheep with PrP
genotypes known until now to confer natural resistance to conventional
scrapie. Here we report that both Nor98 and discordant cases, including
three sheep homozygous for the resistant PrPARR allele (A136R154R171),
efficiently transmitted the disease to transgenic mice expressing ovine PrP,
and that they shared unique biological and biochemical features upon
propagation in mice. These observations support the view that a truly
infectious TSE agent, unrecognized until recently, infects sheep and goat
flocks and may have important implications in terms of scrapie control and
public health.

----------------------------------------------------------------------------
----

Author contributions: H.L. designed research; A.L.D., V.B., O.A., F.R.,
T.L.L., J.-L.V., and H.L. performed research; T.B., B.B., P.S., and S.L.B.
contributed new reagents/analytic tools; V.B., O.A., and H.L. analyzed data;
and H.L. wrote the paper.

A.L.D. and V.B. contributed equally to this work.

To whom correspondence should be addressed.

Hubert Laude, E-mail: laude@jouy.inra.fr

www.pnas.org/cgi/doi/10.1073/pnas.0502296102

http://www.pnas.org/cgi/content/abstract/0502296102v1

12/10/76
AGRICULTURAL RESEARCH COUNCIL
REPORT OF THE ADVISORY COMMITTE ON SCRAPIE
Office Note
CHAIRMAN: PROFESSOR PETER WILDY

snip...

A The Present Position with respect to Scrapie
A] The Problem

Scrapie is a natural disease of sheep and goats. It is a slow
and inexorably progressive degenerative disorder of the nervous system
and it ia fatal. It is enzootic in the United Kingdom but not in all
countries.

The field problem has been reviewed by a MAFF working group
(ARC 35/77). It is difficult to assess the incidence in Britain for
a variety of reasons but the disease causes serious financial loss;
it is estimated that it cost Swaledale breeders alone $l.7 M during
the five years 1971-1975. A further inestimable loss arises from the
closure of certain export markets, in particular those of the United
States, to British sheep.

It is clear that scrapie in sheep is important commercially and
for that reason alone effective measures to control it should be
devised as quickly as possible.

Recently the question has again been brought up as to whether
scrapie is transmissible to man. This has followed reports that the
disease has been transmitted to primates. One particularly lurid
speculation (Gajdusek 1977) conjectures that the agents of scrapie,
kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of
mink are varieties of a single "virus". The U.S. Department of
Agriculture concluded that it could "no longer justify or permit
scrapie-blood line and scrapie-exposed sheep and goats to be processed
for human or animal food at slaughter or rendering plants" (ARC 84/77)"
The problem is emphasised by the finding that some strains of scrapie
produce lesions identical to the once which characterise the human
dementias"

Whether true or not. the hypothesis that these agents might be
transmissible to man raises two considerations. First, the safety
of laboratory personnel requires prompt attention. Second, action
such as the "scorched meat" policy of USDA makes the solution of the
acrapie problem urgent if the sheep industry is not to suffer
grievously.

snip...

76/10.12/4.6

http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf

TSS

##################### Bovine Spongiform Encephalopathy #####################

CJD WATCH MESSAGE BOARD
TSS
Prion infections, blood and transfusions Aguzzi and Glatzel
Sat Jul 8, 2006 12:18
68.238.108.213

Prion infections, blood and transfusions

Adriano Aguzzi* and Markus Glatzel

Prion infections lead to invariably fatal diseases of the CNS, including

Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform

encephalopathy (BSE), and scrapie in sheep. There have been hundreds

of instances in which prions have been transmitted iatrogenically among

humans, usually through neurosurgical procedures or administration of

pituitary tissue extracts. Prions have not generally been regarded as bloodborne

infectious agents, and case-control studies have failed to identify

CJD in transfusion recipients. Previous understanding was, however,

questioned by reports of prion infections in three recipients of blood

donated by individuals who subsequently developed variant CJD. On

reflection, hematogenic prion transmission does not come as a surprise, as

involvement of extracerebral compartments such as lymphoid organs and

skeletal muscle is common in most prion infections, and prions have been

recovered from the blood of rodents and sheep. Novel diagnostic strategies,

which might include the use of surrogate markers of prion infection, along

with prion removal strategies, might help to control the risk of iatrogenic

prion spread through blood transfusions. ...

snip...

INTRODUCTION

Prion diseases, also termed transmissible

SPONGIFORM ENCEPHALOPATHIES, constitute

a group of neurodegenerative conditions that

are transmissible within and between mammalian

species. A characteristic of these diseases is

the accumulation of a misfolded prion protein,

PrPSc, which is a post-translationally modified

form of the host-encoded prion protein (PrPC).

The processes underlying PrPSc formation

remain enigmatic, but there is little doubt that

a conformer of PrPC, which might exist in an

oligomeric form,1 is identical to the infectious

entity.2 Prions damage the brain by transmitting

toxic signals to cells expressing PrPC.3

Although genetic evidence has been taken

to indicate that human prion diseases have

been with us since prehistoric times,4 the first

documented cases of Creutzfeldt-Jakob disease

(CJD) date back only 85 years.5-7 Since then, it

has become obvious that human prion diseases

have three distinct etiologies: they can arise in the

absence of any documented exposure to infectious

prions as sporadic CJD (sCJD), as an autosomal

dominantly inherited disease in the case

of genetic, or familial, CJD (gCJD/fCJD), or as

an acquired condition in the case of IATROGENIC

and variant CJD (iCJD, vCJD), or kuru, which

resulted from cannibalism.8

Some prion diseases that occur in animals

might have been recognized several centuries

ago, as suggested by early descriptions of sheep

diseases that seem to correspond to scrapie.

Most prion diseases affecting animals, however,

were discovered relatively recently.6 A transmissible

spongiform encephalopathy affecting

cattle (bovine spongiform encephalopathy,

or BSE) has caused a massive epidemic in

European countries, affecting around 2 million

animals.9 Epidemiological, biochemical, neuropathological

and transmission studies have

substantiated the concern that BSE prions might

have crossed the species barrier between cattle

and humans, resulting in a novel form of human

prion disease, vCJD.10-13 During 1996-2001, the

incidence of vCJD in the UK rose year upon year,

evoking fears of a large upcoming epidemic.

Since 2001, however, the incidence of vCJD in

the UK appears to have been stabilizing, indicating

that the extent of the epidemic might be

limited.14 As might be expected for in frequent

stochastic events, the numbers of new cases of

vCJD fluctuate from year to year. For example,

data available on the web page of the National

CJD Surveillance Unit15 show that the number

of onsets of vCJD was higher in 2004 than it was

in 2003, but this is not necessarily indicative of

an upward trend.

It must be assumed that a number of asymptomatic

carriers of vCJD exist in human populations

that have been exposed to BSE. The

existence of such a chronic carrier state is a

logical and unavoidable consequence of the

long incubation time of prion diseases, which

is typically in the order of several years and--

in the case of oral exposure to prions--can

reach several decades. Consequently, anybody

who has contracted the infection but has not

developed clinical signs and symptoms might

be consider ed a carrier. Some of these carriers

are likely be 'preclinical', and will proceed,

in due course, to the development of disease.

Alternatively, it is conceivable that the carrier

state can persist for an indefinite period of

time, in which case infected individuals could

be regarded as 'permanent asymptomatic

(sub clinical) carriers'. Studies performed in

rodents indicate that the permanent subclinical

carrier state might be a common phenomenon,

such as occurs when immune deficient mice

are exposed to prions.16 Unlinked anonymous

screens for hallmarks of prion infection in

archival tissues have suggested that the prevalence

of individuals with sub clinical vCJD might

be higher than previously antici pated, and could

reach 237 cases per million individuals.17

The recent discovery of transmission of vCJD

via blood in three individuals indicates with

near certainty that blood-borne prion transmission,

in conjunction with an unknown

prevalence of vCJD-infected carriers, leads

to secondary transmission of host-adapted

prions.18 Consequently, the vCJD epidemic

might be prolonged, or, in the worst-case

scenario, vCJD be rendered endemic and selfsustained.

In this article, we review how prions

could act as blood-borne infectious agents, and

consider strategies aimed at minimizing the risk

of secondary trans mission of prion diseases.

TRANSMISSION OF PRION DISEASES

IN HUMANS

The cause of most human prion diseases is

unknown. In the case of sCJD, the term 'sporadic'

is used as a euphemism, meaning that we have

no idea about the origin of this form of CJD. By

contrast, gCJD always segregates within families

with mutations in the gene encoding the prion

protein (PRNP), suggesting that these mutations

are causally involved in disease pathogenesis. As

no families have been described in which gCJD

segregates with mutations in genes other than

PRNP, it has been difficult to use human genetics

to understand the pathogenesis of prion diseases.

The discovery of PRNP mutations in gCJD has

led to the proposal that at least some cases of

sCJD might be due to somatic PRNP mutations

analogous to those found in the germline of

gCJD patients. It is equally possible, however,

that some of the cases of alleged sCJD derive

from hitherto unrecognized infectious causes.

In apparent agreement with the 'intrinsic'

origin of sCJD, which accounts for more than

90% of all human prion diseases, epidemiological

studies were not able to identify a

conclusive link between this form of CJD and

external risk factors.19 This fact is reflected in

the pathological and biochemical features of

these diseases. Although low levels of PrPSc and

prion infectivity can be demonstrated in peripheral

sites such as lymphoid organs or skeletal

muscle,20,21 the highest levels of PrPSc and prion

infectivity appear to occur in the CNS. These

facts might account, at least in part, for the lack

of evidence of sCJD transmission by labile or

stable blood products.22 Indeed, several retrospective

studies have failed to identify blood

transfusion or exposure to plasma products as

risk factors for the development of sCJD,19 and

prion diseases appear to be exceedingly rare

in hemophiliacs, a group of patients that is at

particularly high risk of contracting emerging

blood-borne infectious diseases. Although these

studies cannot exclude the possibility that transmission

of sCJD might have occurred through

blood transfusions in rare cases, and despite

the fact that the etiology of sCJD is unclear,

it would appear that transmission of sCJD by

trans fusion of blood or blood products does

not play a major role in the pathogenesis of this